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Full text of "Creative Computing Magazine (August 1981) Volume 07 Number 08"

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the #1 magazine of computer applications and software 



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Computer Simulations 
•Nuclear Power Plant 
•Star Merchant 
•Tree Growth 

Microcomputer < 
'^^Tournament 



Evaluations: 

Apple Silentype Printer 

Tl 99/4 Music Maker 

Hi-Res Cribbage Game 

Apple-oids 

The Last One 






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How to put 
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in your 
adventure games 

How to cram more 
into your Atari 



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TSeiHARDSIIX 




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LE 183 ON READER SERVICE CARD 



Creative Computing 
continues to grow! 



In the evolutionary growth of Creative 
Computing, this coming September will 
mark three important milestones. First, 
the magazine will now be perfect bound 
(a square back like a book). We experi- 
mented with this twice (April and 
September 1980) and reader reaction was 
positive. Hence, we are changing printers 
to R.R. Donnelly in order to provide more 
inside color and perfect binding at a cost- 
effective price. 

Second, Creative Computing will now 
be distributed to newsstands nationally 
by Select Magazines, Inc. We have experi- 
mented in several local areas— Cambridge, 
Chicago and the Bay area— and sales were 
most encouraging. We expect this move 
to add 20- to 30.000 to our circulation 
thus bringing it to 120,000 plus. 

Third, we are publishing a French 
language edition. Actually, it is Publications 
Internationals in Paris who will publish 
and distribute this edition. Initial paid 
circulation is projected at 50,000. Adver- 
tisers who want to consider advertising in 
this edition should drop us a line for 
rates. 



Complete 6-year Index 

Find it Fast! 



Our new 6-year cumulative index lists 
every article, program and review that has 
appeared in Creative Computing from its 
inception in November 1974 to December 
1980 The index lists not only the issue in 
which an article appeared but a cross 
reference to The Best of Creative Computing. 
Volumes 1 . 2 and 3. It also lists all the articles 
in ROM magazine 

Articles are classified by subject area and 
listed by title and author Over 3500 separate 
items are included Note: the index does 
not include a cross reference to author 

Looking for information on computers in 
education - ' You II find 76 articles and 155 
application programs. How about art and 
graphics 7 You II find 44 entries In the market 
for a computer? You find 82 hardware 
evaluations and 94 of software 

Price of this huge index is just $2 00 
Even if you ve been a reader for only a year 
or two you II find the index of great value 
Orders yours today 

creative 
computing 

Morns Plains. NJ 07950 

v »- 

CIRCLE 300 ON READER SERVICE CARD 



Attention: Programmers! 




Best sellers. Bolts out of the blue? Not 
everyone can write Super Invader or Air 
Traffic Controller or Stock and Options 
Analysis. Or can they? 

At this point, we don't know. We sus- 
pect that many potential best selling pro- 
grams are lurking in the back of some- 
body's computer and even more are lurk- 
ing in the back of somebody's mind. 
Either way, they're not doing anyone 
much good. 

I could get carried away about this— 
everyone is a potential Hemingway or 
Tahito— but let's cut it short. Send your 
programs, well-documented of course, 
with a stamped return envelope to us. A 
publisher of another well-known maga- 
zine promises that every program author 
will get rich beyond his wildest dreams. 
We don't. But we do pay an advance on 
accepted programs. Most other compan- 
ies don't. We also pay a generous royalty 
(which has produced a nice income for 
the authors of Super Invader. Adventure, 
Air Traffic Controller and others). We'll 
do our best to get your program into 
production as soon as possible. We'll pro- 
mote it widely. And. if we can, we'll make 
you famous and rich— in that order. 

Send your programs on disk (prefer- 
ably) or tape (ugh) with documentation 
(typed double spaced) and stamped 
return envelope to Creative Computing 
Software Submissions. 39 East Hanover 
Avenue. Morris Plains. NJ 07950 USA. 



J 



fountain Computer 
put it all together 
for you. 




The CPS MultiFunctlon Card 

Three cards in one! The Mountain Computer CPS MultiFunction Card provides all the capabilities of a serial interface, parallel 
output interface and real-time clock/calendar— all on one card— occupying only one slot in your Apple II •. Serial and Parallel 
output may be used simultaneously from CPS. CPS is configured from a set-up program on diskette which sets the parameters 
isuch as baud rate, etc for all functions contained on the card and is stored in CMOS RAM on the card. Once you have 
configured your card, you need never set it up again. You may also change parameters from the keyboard with control 
commands. All function set-ups stored on-board are .battery powered for up to two years. "Phantom slot" capability permits 
assigning each of the functions of CPS to different slots in your Apple without the card actually being in those slots! For 
example, insert CPS in slot #4 and set it up so that is simulates a parallel interface in slot #1 and a clock in slot #7 and leave the 
serial port assigned to slot #4. CPS's on-board intelligence lets it function in a wide variety of configurations, thereby providing 
software compatibility with most existing programs. "We've put it all together for you"— for these reasons and many more! 
Drop by your Apple dealer and see for yourself how our CPS MultiFunction Card can expand the capabilities of your Apple and 
save you a great deal of money as well! 



Calendar/Clock 

• One second to 99 years 

• Battery backed-up 2 years 

• Two AA standard alkaline batteries 
for back-up provided 

• Compatible with MCI Apple 
Clock'" time access programs 



dhb 



Parallel Output 

• Features auto-line feed. Apple 
tabbing, line length, delay after 
carriage return, lower to upper 
case conversion 

• Centronics standard— 
reconfigurable to other standards 

• Status bit handshaking 



Mountain Computer 

AS INCORPORATED 



300 El Pueblo Scotts Valley, CA 95066 
408 438-6650 TWX: 910 598-4504 



SPECIAL 

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Serial Interface 

• Features auto-line feed, trans- 
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output characters, simultaneous 
serial/parallel output, lower to 
upper case conversion, discarding 
of extraneous LFs from serial input 

• Uses the powerful 2651 serial 
PCI chip 

• 16 selectable internal baud rates— 
50 to 19.2Kbaud 

• Half/Full duplex terminal operation 

• I/O interface conforms to RS-232C 

• Asynchronous/Synchronous 
operation 



"Apple Clock was the trademark of Mountain Computer Inc " Apple and Apple II are registered trademarks of Apple Computer Inc 

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evaluations & profiles 

-1 "J Apple Silenty pe and Graphic Writer Walker 

The prince and the paper 

20 Hi-Res Cribbage Archibald 

Pegging for more 

00 Appto-olds Lubar 

On the rocks 

24 Th. Last On. Blank 

A program to write programs 

26 Tl 99/4 Music Makor Linderholm 

Deep in the heart of Texas 

OQ Of Cabbages and Kings Kimmel 

Second Computer Chess Tournament 

articles 

28 Th. National Computer Conference Staples 

New products abound 

Kg The Origin of Spacewar! Graetz 

As told by one who was there 

70 Putting Adventure in Adventure Games Plamondon 

73 RAM Cram Techniques for Atari Howell 

Original Adventure in 32K 

94 New Man ° n Llne Staples 

Heath president Bill Johnson 

99 Strategies for Successful Simulation Wolff 

1 08 Jh9 Natlona ' THS-80 Show Blank 

Private audiences with top programmers 






AUGUST, 1981 
VOLUME 7, NUMBER 8 

Creative Computing magazine is published monthly by Creative Computing. P.O. 
Box 789-M. Morristown. NJ 07960. (Editorial office 39 East Hanover Ave . Morris 
Plains. NJ 07950 Phone (201) 540-0445 ) 

Domestic Subscriptions 12 issues S20; 24 issues $37; 36 issues (53 Send 
subscription orders or change of address (P O Form 3575) to Creative Computing 
P.O. Box 789-M. Morristown. NJ 07980 Call 800-631-81 1 2 loll-lree (in New Jersey 
call 201-540-0445) to order a subscription (to be charged only to a bank card) 

Controlled Circulation paid at Richmond. VA 23228. 

Copyright ©1981 by Creative Computing All rights reserved. Reproduction pro- 
hibited Printed in USA 



applications & software 

110 How to Solv « It-Part 8 Piele 

1 22 jT ™ He,t 

A forest simulation for the PET 

•1 29 Star Mefcn « nt Johnson 

A futuristic trade simulation 

1 44 PET Nucloar Power Plant Smith 

You're in charge 

1 56 Stonwilie Manor Jensen 

Find the deed and it's yours 



departments 

ft Dateline: Tomorrow Ahl 

News and views 

1 1 Input/Output Readers 

1 4 Notteos etal 

1 63 Computer Store of the Month Gibbons 

1 66 Now Product* Staples 

1 83 EWectlv « Writing Delp 

Ken's Compact Comma Calculator 

1 88 TRS-80 Strings Gray 

,0 ° The Color Computer 

200 ° ut P° s,: A,ari Small 

* w More on the display list 

OAQ Intelligent Computer Gam.* Levy 

fcw *» Go-Moku 

216 Puzzl** * Problems Townsend 

21 8 Book Reviews Q r ^y 

224 lndex to Advertisers 



the coven 



The cover is an original painting by Rosemarie Dalbo of Beacon, 
NY. 



AUGUST 1981 



■ 



starr 



Publisher/Editor-in-Chief David H. Ahl 



Editorial Director 
Editor 

Associate Editor 
Managing Editor 



Contributing Editors 




Editorial Assistant 
Secretary 



George Blank 

Elizabeth Staples 

David Lubar 

Peter Fee 

Charles Carpenter 
Thomas W. Dwyer 
Stephen B. Gray 
Glenn Hart 
Stephen Kimmel 
Harold Novick 
Peter Payack 
Alvin Totller 
C. Barry Townsend 
Gregory Yob 
Karl Zinn 

Andrew Brill 
Elizabeth Magin 



Production Manager 
Art Department 



Typesetters 



Laura MacKenzie 

Diana Negri 

Chris Demilia 

Joanne Fogarty 

Glenn McFall 

Jean Ann Vokoun 
Maureen Welsh 



Advertising Sales 



Marketing 



Charles Coffin 

Renee Fox Christman 

Jetf Horchler 

Earl Lyon 
Laura Conboy 



Creative Computing Press 

Managing Editor ' Edward Stone 



Software Development 



Software Production 



Chris Vogeli 

William Kubeck 

Kerry Shetline 

Owen Linderholm 

Eric Wolcott 

Neil Raddick 

Bill Rogalsky 

Rita Gerner 

Heather Ever ill 



Operations Manager 

William L. Baumann 

Personnel 4 Finance Patricia Kennelly 

Ethel Fisher 



Bookkeeping 
Retail Marketing 

Circulation 



Office Assistants 



Order Processing 



Shipping & Receiving 



Jennifer Burr 
Laura Gibbons 

Frances Miskovich 

Dorothy Staples 

Moira Fenton 

Carol Vita 

Sandy Riesebeck 



Rosemary Bender 

Linda McCatharn 

Diane Feller 

Mary McNeice 

Jim Zecchin 

Ralph Loveys 

Gail Harris 

Linda Blank 

Mark Smith 

Ronald Thorburn 

Karen Brown 

Mark Elk) 

Scott McLeod 

Nick Ninni 

Mark Archambault 

Mike Gribbon 

Ronald Antonaccio 



advertising sales 

Advertising Coordinator 

Renee Christman 
Creative Computing 
P.O. Box 789-M 
Morristown, NJ 07960 
(201)540-0445 

Westorn States 

Jules E. Thompson, Inc. 

1 290 Howard Ave., Suite 303 

Burlingame. CA 94010 

(415)348-8222 

In Texas call (713) 731-2605 

Southern California 

Jules E. Thompson, Inc. 

2560 Via Tejon 

Palos Verdes Estates, CA 90274 

(213)378-8361 

Mid-Atlantic, Northeast 

CEL Associates. Inc. 
27 Adams Street 
Braintree, MA 02184 
(617)848-9306 

Midwest 

Ted Rickard 
435 Locust Rd. 
Wilmette. IL 60091 
(312)251-2541 

New York Metroplitan Area 
Nelson & Miller Associates, Inc. 
55 Scenic Dr. 

Hastings-on-Hudson, NY 10706 
(914)478-0491 

Southeast 

Paul McGinnis Co. 
60 East 42nd St. 
New York, NY 10017 
(212)490-1021 ( 

attention authors 

Creative Computing will not be 
responsible for the return of unsolicited 
manuscripts, cassettes, floppy disks, pro- 
gram listings, etc. not submitted with a 
self-addressed, stamped envelope. 

OK to reprint 

Material in Creative Computing may 
be reprinted without permission by 
school and college publications, per- 
sonal computing club newsletters, and 
nonprofit publications Only original 
material may be reprinted; that is. you 
may not reprint a reprint Also, each re- 
print must carry the following notice on 
the first page of the reprint in 7-point or 
larger type (you may cut out and use this 
notice if you wish): 

Copyright ©1981 by Creative Com- 
puting. 39 E. Hanover Ave., Morris 
Plains. NJ 07950. Sample issue $2.50, 
12-issue subscription $20. 

Please send us two copies of any publi- 
cation that carries reprinted material 
Send to attention: David Ahl. 

microform 

Creative Computing is available on 
permanent record microfilm For com- 
plete information contact University mi- 
crofilms International. Dept FA. 300 
North Zeeb Road. Ann Arbor. Ml 48106 
or 1 8 Bedford Road . London WC 1 R 4E J . 
England 



foreign customers 

Foreign subscribers in countries listed below 
may elect to subscribe with our local agents using 
local currency. Of course, subscriptions may also 
be entered directly to Creative Computing (USA) 
m US dollars (bank draft or credit card) All 
foreign subscriptions must be prepaid 

Many foreign agents stock Creative Computing 
magazines, books, and software However, please 
inquire directly to the agent before placing an 
order Again, all Creative Computing products may 
be ordered direct from the USA— be sure to allow 
for foreign shipping and handling 



Hms* 


C »29 


n/a 


2-year 


ss 


n/a 


3-year 


SO 


n/a 


AUSTRALIA 


(A 


SA 


1-year 


28 


52 


2-year 


54 


101 


3-year 


78 


150 


ELECTRONIC CONCEPTS PTY . LTD 




Attn Rudi Hoess 






Ground Floor 55 Clarence St 






Sydney. NSW 2000. Australia 






ENGLAND 


t 


t 


1-year 


1250 


2100 


2-year 


2400 


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3-year 


34 50 


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CREATIVE COMPUTING 






Attn: Hazel Gordon 






27 Andrew Close 






Stoke Golding. Nuneaton CV13 6EL 




FRANCE 


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SYBEX EUROPE 






14/18 Rue Plane hat 






75020 Pans. France 






GERMANY 


dm 


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1-year 


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88 


2-year 


98 


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3-year 


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250 


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Ing W Holacker 






8 Munchen 75 






Postlach 437. West Germany 






HOLLAND. BELGIUM 




1 


1-year 




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2-year 




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3-year 




33/ 


2XF COMPUTERCOLIECTIEF 




Attn F deVreete 






Amstel312A 






101 7 AP AMSTERDAM. Holland 




ITALY 


IL 


IL 


1-year 


34.000 


52.000 


2-year 


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3-year 


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ADVEICOSRL 






Via Emilia Ovest. 128 






43018 San Pancrano (Parma) Italy 




Attn Giulio Benelhni 






JAPAN 


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34.400 


ASCII PUBLISHING 






Aoyama Building 5F 






5-16-1 Minami Aoyama. Minato-Ku 




Tokyo 107. Japan 






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INTEGRATED COMPUTER SYSTEMS 


INC 


Suite 205 Limkelkai Bdg . Ortigas Ave 




Greenhills P O Bon 4S3. San Juan 




Metro Manila 31 13. Philippines 




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123 


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CREATIVE COMPUTING 






P O Bon 789-M 






Morristown. N J 07040. USA 







CREATIVE COMPUTING 



Terminals and Printer 



\tuw I data 

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Z1 9 Video Terminal 



List $995 




OUR PRICE 

$799 



Limited Time 



Intertec 

NEW INTERTUBE III 

u.t $996 ONLY $749 

12" display, 24 x 80 format, 18-key numeric 
keypad. 128 upper/lower case ASCII charac- 
ters. Reverse video, blinking, complete cursor 
addressing and control. Special user-defined 
control function keys, protected and unpro- 
tected fields. Line insert/delete and character 
insert/delete editing, eleven special line draw- 
ing symbols. 



TELEVIDEO TVI-912C 




Upper and lower case. 15 baud rates: 75 to 
19.000 baud, dual intensity. 24 x 80 character 
display, 12 x 10 resolution. Numeric pad. Pro 
grammable reversfble video, auxiliary port, 
self test mode, protect mode, block mode, 
tabbing, addressable cursor. Microprocessor 
controlled, programmable underline, line and 
character insert/delete. "C" version features 
typewriter-style keyboard. List $950 

CALL FOR PRICE 

920C (with 11 function keys, 6 edit keys and 
2 transmission mode keys. List $1030 

CALL FOR PRICE 

950C LlSt $1195 CALL FOB PRICE 



HAZELTINE 1500 



PAPER TIGER 



Call 

For 

Price 




1410 w/numeric keypad. List $900 CALL 

1420 w /lower case and numeric pad ... CALL 

1510, List $1395 CALL 

1520, List $1650 CALL 

SOROC 

IQ-120 

List $995 




SPECIAL 

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10.135 
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IQ 140 List $1495 
SPECIAL $1149 



CENTRONICS 

PRINTERS 

NEW 730. parallel, friction, Iracloi $599 

NEW 737 parallel, friction, Iractoc $799 
779-2 w/tractor (same as TRS 80 i 

Printer I). List $1350 $799 

704-9 RS232 180CPS $1595 

704-11 Parallel 180CPS $1695 



NEC SPINWRITER 



TM 




Terminal /Keyboard as well as 

RO Printer Only models available. 

CALL FOR PRICES! 



IDS 445 PAPER TIGER 

IDS 445G PAPER TIGER 
Buffer w/graphics option, incl. buffer . . . 
NEW IDS 460/560 
QUALITY PRINTING AT MATRIX 
SPEED - LOGIC SEEKING 
PROPORTIONAL SPACING 
w auto test justification 
NEW IDS PAPERTIGER 460 List $1295 . 
NEW IDS PAPERTIGER 460G List $1394 

NEW IDS 560G List $1794 

TRS 80 cable 



$698 
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$1099 

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TI-810 




Tl 810 Basic Unit. $1895 . $1595 

Tl 810 w full ASCII (Lower case), vertical 

forms control, and compressed print $1795 

Tl 820w/lower case List $1995 $1645 

Tl 820w/full ASCII, forms control, 

compressed print List $2150 . $1795 

TI-745 Complete printing terminal 
with acoustic coupler. List $1695 .... $1399 

^NflD€X 

DP9500/DP9501 PRINTCRS 

DP-9500. List $1650 $1349 

DP-9501. List $1650 $1349 

ANADEX dp 8000 

80 Col. Dot Matrix $849 

OKI DATA 

Microline 80 ONLY $499 

Tractor Feed Option $109 

Serial interface $ 99 

Microline 82 $679 

Microline 83 $1069 

AXIOM IMP I $699 

Epson MX-80 List $645 $499 



Above prices reflect a 2% cash discount (order prepaid prior to shipment). Add 2% to prices for credit 
card orders, C.O.D.'s, etc. Prices are fob. shipping point. Prices are subject to change and offers 
subject to withdrawal without notice. WRITE FOR FREE CATALOG. 



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pc w . . . dateline : tome wo w, 



ANOTHER BUBBLE BURSTS 



David H. Ahl 



In the June column I mentioned that Rockwell was pulling out of the bubble memory 
arena. Now they have been followed by industry giant Texas Instruments. This leaves 
Intel and National Semi as the chief producers of bubble memory components with Motorola 
still promising a product announcement before year's end. Thus, it looks less likely that 
a solid state device will replace disk storage devices on a mass level 1n the near future 
as was so widely forecast as little as 18 months ago. 

TI 99/4 OUT. TI 99/4A IN. 



Plagued by buyer resistance to its strange keyboard and high list price, TI plans 
to withdraw the 99/4 and replace it with an updated model, the 99/4A. The new machine has 
a standard keyboard with upper and lower case and carries a retail price of $525. This 1s 
$125 less than the current, twice reduced price of the 99/4. 

Will a 16K 99/4A sell at $525? Direct competitors include the 16K Atari 400 at 
$399 (but with a membrane keyboard), the 16K TRS-80 Color Computer at $399 and the 
Commodore VIC-20 with 5K at $299. Our verdict: too little and too late. 

W ITHER IBM? 

In April I mentioned that IBM has something small up its corporate sleeve. The 
details are beginning to shape up: 1t will be based on the 16-bit Intel 8088 mpu and be 
able to address up 256K. Two 5"-l/4" floppy disk drives are included, one of which can be 
replaced by a Winchester. The operating system is similar to CP/M. Price 1s anybody's 
guess. 

AND XEROX 



Hot on the heels of the Xerox Star announcement (see NCC Report on page 28) comes 
another even lower end machine, the 820, designed to compete with intelligent word 
processing machines like the IBM Displaywriter, Wang and CPT. Like the Star., it can hook 
in to the Ethernet network. 

Based on a Z80A, the machine uses the CP/M operating system. This positions 1t 
squarely 1n the midst of the microcomputer market which, to date, has avoided the 
attention of the giants. Base price of the machine with a dual disk drive and display is 
$2995; with printer this goes to $6000. 

THE BIZARRE WORLD OF LAWYERS AND PATENTS 

Patent 4,235,442 was issued to Fidelity Electronics covering "electronic board 
game systems such as games normally played between two competitors, wherein the 'game' 
substitutes for the second competitor." 

A Fidelity press release proclaims that "patent infringement proceedings are being 
considered against a number of companies, representatives, distributors, wholesalers, and 
retailers." Indeed, an entire industry is vulnerable. 

The next thing you know someone will be issued a patent covering all computer 
games in which the 'game' plays the role of the second competitor. "Ridiculous, you say. 
But apparently the lawyers don't think so. It's a bizarre world in which we live. 

D ON'T ASK 

An alarming number of readers have called or written asking for further 
information on items mentioned in this column. "Alarming" because I can't possibly answer 
all the Inquiries. And for the most part, I rarely have much additional information. As 
soon as a product becomes commercially available, we will review it in Creative. 

If you have any information that ought to appear in this column, please send 1t 
along. Thanks! 















CREATIVE COMPUTING 

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Kavcs of 
Karkljar; 



At La?rTt)e Sequel 
You've Waited For! 



Level- I O "' the < (impart) thai 
brouyht \ i>u Dragon fire now 
presents the Kaves ol Harkhan 

rhe Warrioi the Huntress the 
Wizard tin- I. II and the Dwarl sui 



i rightenlng Journey ih 

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it newest mission is to save 
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Maldamere before his un 
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• iluiii to subterranean hazards 
like crumbling u.iiis decaying 
st.iiis Falling boulders and t<-.u 
some nighl < rcatures. 

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tain Maldamere s s|iir it t 
short time. You must wend youi 
wa) through the k.iws .is «j u i< k 
K ,is possible before Maldamere 
consumes the Wizard. Youi sole 
pui pose is tu pla< e a m.i<ii( .il 
slum' on the biei ol Maldamere 
.it the top ul % lt Karkhan 

haves ol Harkhan is just ,is 
allenging ,is l)i agon Fire Its 
imation It i -Res 3-D <\t aphii s 
il time < tnisti. lints ,i<i<i extra ex 
emenl l.\ en il s mi \ c nev ei 



division ol DAKIN5. 



CIRCLI 125 ON Rf ADtH AMD 



put... input/output. ..in 




XOR Size 

Dear Editor: 

I enjoyed Charles Noah's article. "Protect Those Data 
Files. "in the March issue. 

Below is an alternate program for encoding/decoding 
strings using XOR's. It has the same effect that Mr. Noah's 
program would if a separate key were provided for each 
position of the character string. However, this program 
requires only one key. This key, which may be integer or non- 
integer, is used to "seed" the random number generator. Many 
Basic interpreters allow use of a seed. This program is written 
in Microsoft Basic. 

10 INPUT "ENTER YOUR KEY ":KV 

20 LINE INPUT "ENTER A STRING: ";AS 

30 GOSUB 9000 ' SCRAMBLE THE STRING 

40 PRINT "SCRAMBLED STRING: ":AS 

50 GOSUB 9000 ' DE-SCRAMBLE THE STRING 

60 PRINT "ORIGINAL STRING: ";A$ 

70 END 

9000 REM ENCODE/DECODE STRING AS 

90I0X = RND(-ABS(KVH 

' RESTART RANDOM GENERATOR 

9020 FOR 1= 1 TO LEN( AS) 

9030 MID$<AS.I.l)=CHR$<ASC<MID$lAS.I. Ill XOR INT 

<256»RNDHHI 
9040 NEXT I 
9050 RETURN 

Paul Schaefer 
2315Crestbook 
Hint. MI 48507 



In The Cards 

Dear Editor: 

If hackers wish to re-invent the wheel, fine; let them. But 
Rogowski is stone chipping with his fingernails in "Cat Card" 
{Creative Computing. May 1981). Why a manual system when 
his program can search, add. re-alphabetize, delete, or print- 
out a bibliography by author, title, type, or "who has got my 
stuff?" if preferred? 

Since assigned numbers and subjects are so readily available, 
so expandable, the thought of resystematizing anything boggles 
the mind. His little I ! I caution, "always be aware of where the 
card . . . will fit." is revelation enough. 

We produce inventories, print-outs of lists from all keyed 
information, and could do cards, if we needed them. Rogowski 
reminds one of those monks who copied all early printed 
books back on to parchment, hating to give up the old ways. 
Both his approach and his product deny his computer's great 
facility at cataloging. 

Betty M. Minemier 

Librarian Media Specialist 

Junior High School 

Dansville. NY 14437 

Under Control 

Dear Editor: 

There is one problem that has been puzzling me for a long 
time. It is how to put a password on vour program to prevent 
the running of it and not be able to stop it. Also accompanying 
this problem hand-in-hand is the question on how to prevent 
the person from just loading the program, listing it and take 
out the password routine and then run it and save it. I have 
had several experiences of people stealing my programs from 
my diskette. The computer I am refering to is the Apple II. I 
hope you are able to help me on this problem. I have written 
to the company but in vain. Thank you for your time. 

Marco Matchefts 
P.S. A perfect example of an excellent routine is Applechess 
2.0. 

There are many ways to protect programs. The simplest 
technique to use with Apple disks is to add control characters 
to program titles when saving the programs. These characters 
won't appear on the screen during a CATALOG list. The 
only problem is that you have to remember both which 
characters were used and where in the title they were used, or 
you won 't be able to run your own program. To enter the 
control characters, just type them using any non-reserved 
letter along with the control key. Certain characters tsuch as 
control-X or control-H) can 't be entered through the keyboard, 
since they perform certain functions. There are ways to enter 
reserved characters, but that goes beyond the scope and 
space of this reply. This type of protection can keep someone 
from running your program, but it doesn 't help with the 
problem of how to allow someone to run. but not to copy, 
your program. If there is reader interest. Til try to cover some 
protection techniques in detail. —D.L. 



AUGUST 1981 



11 



el... in put/output... in 



Imaginary Strings 



Dear Editor: 

After reading the article on APF'S Imagination Machine. 
May '80, 1 became interested in it. 

Looking further I found out that the statement about the 
lack of string functions was misleading. Although it wasn't 
very clear in the Basic Manual, it is possible. 
Left $(AS.X) becomes Dim B$(X-1): B$=A$ 
Right $( A$.X) becomes Y=Len( A$): Dim B$(X-1 ): 

B$=AS(L-X-lt 
Mid S(AS.X.Y) becomes Dim B$(Y-X): B$=A$(X-1) 
where B$ represents the new string fragment. 

Gregory Forseth 

9240 Golden Valley Rd. 

Golden Valley. MN 55427 



Pardon Me Boys, Is That The Chart 
That Knew The Future? 

Dear Editor: 

I am a "Chartist," and after reading the 3rd paragraph in 
the disclaimer following the article "Investing in Mutual Funds" 
by John S. Browning (May 1981. Creative Computing) I feel 
like I practice Witchcraft and await burning at the stake. You 
have touched on the war between the Fundamentalist and the 
Chartist: between good and evil. 

Yes. we do claim our chart formations act as a guide in 
stock selections and timing, but to say without proof as Mr. 
Browning did that "few statisticians believe in these methods" 
is not fair play in anyone's cauldron! 

A quick scan of Financial publications will reveal articles 
by well-known professionals on the merits of technical analysis. 
True, the method is not infallible but then neither is fundamental 
analysis. 

Patrick J. Calabrese 

906 E. 21st St. 

Erie. PA 16503 




Satisfied Customer 

Dear Editor: 

I was quite delighted to see your recognition of "The 
Computer Works" as your Computer Store of the Month in 
the May issue of Creative Computing. Since 1977 I have been 
a very satisfied customer of Herman Axelrod. He started me 
in personal computing, guided me correctly in the selection 
of hardware and has offered me invaluable advice regarding 
software and problem solution ever since. His associates are 
knowledgeable and helpful. His service organization is excellent, 
prompt and experienced. 

As a complete neophyte when 1 started, to me one of the 
most important characteristics Herman exhibited, in addition 
to his honesty and knowledge, was and has been his patience. 

In my opinion, the Computer Works can stand as an excellent 
example of what a computer store should be. 

Carlos E. Milner Jr. 

1318 S. Crystal Way 

Aurora. CO 80012 



©Creative Computing 



M CMfe . 



Radical Problem 

Dear Editor: 

I own an Apple and I have just recently found another 
Applesoft bug. Have you ever noticed that program A will 
not work with any number unless it is a multiple of 4. This 
program will always tell you that the square of your number is 
a non-integer, unless of course you enter a multiple of 4 (like 
4 or 16 or 64). Program B seems to solve this problem. This 
program will correctly tell you the nature of the roots no 
matter what the number. Any reason why this is happening? 

Program A. 

10 Input "Numtow? "iA 

20 X - SOR(A> 

30 If X - INT<X) THEN PRINT "Th« root, of thim number >ri 

inttgin' "iGOTO 50 

40 PRINT "Th» roots oi this number »rm non lntvgvrm" 

SO BOTO 10 

60 END 

Program B. 

SAME AS ABOVE. ONLY ADD THIS LINE. 
15 X* - STR»<X> i X - VAL(X») 

Geoffrey Raynor 

935 Park Ave. 

New York. NY 10028 

The problem, and the immunity of powers of four, are 
caused by the way computers handle numbers. A floating- 
point number is stored with more places than are displayed. 
Thus a number that is printed as 3.01 might actually be stored 
as 3.0100000007. The square-root function produces results 
that will be accurate as far as display is concerned. The 
external display SQR(36) will be 6. Internally, the number 
might contain a fractional value in the far end of the decimal 
portion. 

The reason that powers of four don't suffer this problem 
was pointed out to us by Mark Pelczarski. Since the Apple 
converts numbers to binary before carrying out any calculations, 
slight errors will be produced when dealing with floating- 
point values that don't have exact binary equivalents. For 
example. 4.5 decimal is readily translated to 1 00. 1 binary. 

Coupling the difference between internal and external 
handling of numbers with the round-off errors produced by 
conversion from decimal to binary to decimal, you can see 
that numbers displayed as integers might not be stored that 
way. Whenever a test for integers is made, it is best to use an 
intermediate step such as the one used by Mr. Raynor.— D.L 



12 



CREATIVE COMPUTING 




(LISP) 



Introducing 

LISP. The language 

that can think for itself. 

With SmartWare, your micro- 
computer possesses intelligence. Solves 
problems like never before. Actually can learn 
from its mistakes. And educates itself in much 
the same way your brain operates. It's a new 
concept in the way information is handled in 
microcomputers. 

We appropriately called our version of LISP, 
SmartWare. Because it's as limitless as the 
human imagination, mind, memory. 

An advanced, high-level language, LISP was 
first developed for use in artificial intelligence on 
large computers. And now, LISP is available from 
Datasoft for use on the Apple II. 

Store multiple programs in memory. It can 
take it. Program other languages into LISP. It's 
no problem. Because LISP offers greater capacity 
and power. And, it's a faster, more streamlined 
language. For example, just 2 lines in LISP could 
equal hours of BASIC programming. 

The facts: Relational data base capabilities. 
User and program definability. Pattern-directed 



invocation 

language. Uses 

syntax and data 

structures upon which esoteric applications 

may be implemented. Remembers data 

along with "relationships affecting itr Offers 

REAL power to micros. 48K diskette $125.00. 

At MIT, they say LISP is the language of 

the future. 

At Datasoft, we say, why wait. Ask your local 

computer dealer for SmartWare. Right now! And 

turn your computer on to thinking. 

SmarfWuety 

X£^ COMPUTER SOFTWARE 

19519 Business Center Dr.. Norlhridge. CA 91324 

CIRCLE 1 82 ON READER SERVICE CARD ( 2 1 3 )70 1 -5 1 6 1 



Outer through your local aoftwarc drain or tend dm* or money order, pluj «00 aMppIng ind handhna; to Daiaaoft 
•Appk Una returned trademark of Apple Computer*. Inc. 



THELEAST 
EXPENSIVE PROGRAMS 
YOUCANRUY 



P7 hijjh-qu3lit> pri>nr.ims 
for TRS-80. onlv $10 **5 



NewDOS-S0— New Low Price! 

Successor to NewDOS + , nmf pcrkifp for which 
yo» pay |U* lliiwttn, at CIE teat. . . Sill 

SuperPIMS— People's Database 

PIMS has been greatly speeded up and simplified, 
with mar-hint* -UncuaCT* sorts, key debounre, 
optional automatic lowercase (no keying, no 
hardware mod) on labels or reports- Up to 20 
fields, limited by 240 character maximum per 
record. Easy to revise, add records, split or 
merge files, sum or average any fields 
Customized fortape, tape 4 disk, Zoom, TCI Poor 
Man's Floppy, B17, Stringy Floppy— all on one 
tape! As ma l ling labels program, easily manages 
20,00X1 list. CIE does' Advanced labels module to 
com*. $24.95, making system most powerful 
mailer available! on disk, $25 90 

program (CIE) $19.95 ($$1.1$ CA) 

(took, details uses (CIE) $11. 95 ($12 67 CA) 

PASPATCH 

PasPatch, Tape 6P, makes Tandy tiny 
Pascal a powerful disk system! 

Modular Software Assoc $19.95 

Level II Tapes 

'Tiny' Pascal runs on any 16K Level II system, In- 
eludesthe progrsmming structuring capabilities 
of full Pascal, but not data structuring 

Able to compile Z-tO machine cod., prof rams run 
about SX faster than Level II Basic— graphics run 
eight times faster! Requires use of T- Bug (or Tape 
7) and ETASM 
Tape 3. People's Pascal $19 95 

Tape 1, 34 buls, edu . game prog* $10 95 

Tape 2, 77 programs from Osborne book Some 

$10 95 
$10 95 
$10 95 
$10 95 
$10 95 
$10 95 
$39 »5 



Common Basic Programs 
Tap* 5, 24 buls . edu , gam. progs. 
Tap. 7, 31 buls , edu , gam. profs. 
Tap. >. 40. lac 4X tape spMdup 
Tap. 9, 25 buls., edu . gam. progs. 
Tap. 10, incom. tai, rheckg act 
People's Taxmaa, fills out all forms 

Send for free monthly bulletin 
and price list. 

NewDOS- 80 (Model 1 or $7) $111 

DOS-plus (Model 1 or 27) $100 

Percom Doubler $165 

LNW dbl. density, DOS-plus $175 
DoubleZAP-II/80 patch $47.45 

PMC-80 16k computer $610 

PMC -80 expansion (S-100) $380 
32k S-100 RAM card $270 

Percom 40-track drive $375 

Epson MX-80 printer $525 

Centronics 737 printer $850 

Star-writer 2Scps daisy wheel $1,610 
Anadex DP9500 200cps $1,525 



$610 
$57 
$61 

$147 
$90 



EPROM programmer 
ROM extender 
ANALOG input module 
Fastload hi-speed cassette 
CTR-41M cassette deck 
5" Memorex sing den bx 10 $27.50 
5" Memorex dd bx 10 $29.50 
5" FD or 3M cleaning kit $25.50 

Add $1 shipping par order, plus 50 cuts par 
media box or kit. Major items shipped freight 
collect Small items A books, software ahlpped 
poatpatd. 

NEW: Sawd for free monthly catalog 

10% DISCOUNT 
when ordering 3 items 
totaling $50 or more 

All orders charge card, check or m.o. 

Calif, residents add 6 pet tea. Dealer IlK) Invited 

Overa.as, add $1.50 per tap. poateg. 



COMPUTER INFORMATION EXCHANGE 

Box 159 

San Luis Key CA 92068 



s... notices... a 



] 



Popular Computing 
is Popular 

Speaking of other magazines, you may 
have noticed the banner on several covers, 
"Now including Popular Computing." In 
March 1980. we purchased the TRS-80- 
oriented Popular Computing Newsletter. 
Originally, we intended to run a TRS-80 
section in Creative Computing called 
"Popular Computing." However, that 
seemed somewhat narrow so when Chas. 
Andres proposed a regular cartoon strip 
to us, we decided to use the Popular 
Computing name on it. Chas. Andres, 
incidentally, is the author of the computer 
cult cartoon book, CPU Wars, a marvelous 
Adventure-type war between DEC and 
IBM. 

Some four months ago McGraw-Hill's 
Byte subsidiary bought a different Popular 
Computing newsletter/magazine. They plan 
to change the name of onComputing to 
Popular Computing in November and 
increase the frequency from quarterly to 
monthly. As is their way, they have taken 
legal action to prevent us from further 
use of the name. 



To muddy the waters still further, CW 
Communications, publishers of Computer- 
world and Inforworld, also lay claim to 
the name "Popular Computing." They filed 
for a trademark well over a year ago. 

Who really owns "Popular Computing?" 
Only time and the courts will tell. 



Honeywell Correction 

Our Buyer's Guide to Small Business 
Computers (May, 1981 ) contained incorrect 
information concerning the Honeywell 
Level 6 Model 23. The correct information 
is printed below. 



Basic CPU 


$6460 


Diskette Adapter 


1260 


256-K Byte Diskette 


1785 


1 Work Station 


1500 


Work Station Adaptei 


525 


GCOS 6 MOD200 


2090 


TOTAL 


$13,620 



Corrections 

There is a mistake in our response to 
the Hunter High School Computer Room 
on page 1 1 of the June issue. For the new 
PET, POKE 144.88 works better. 




PADt>lfc PlCJ«l- 



The wiring diagram from "Tero's 
Apple" (May 1981) lacked two lines. 
They are shown in the diagram. 



eiBHOM OWCE- 



Oil TeBMIUAI. BOX 



l-O 5CHM1L1 ExrEM6IPM PAPPIE. ^rfv^:ET» 



CIRCLE 124 ON READER SERVICE CARD 



14 



CREATIVE COMPUTING 



Frustrating isn't it! No matter how 
much you speed up your program 
it still seems to take forever to save 
data onto a cassette. Wouldn't it 
be great if someone could design a 
mass storage system with the speed 
of a disk, but at half the cost? 
Exatron did, the Exatron Stringy 
Floppy (ESF) . 

Totally self-contained, the ESF 
is an extremely fast, reliable, and 
economical alternative to cassette 
or disk storage of programs or 
data. All of the ESF's operations 
are under the computer's control, 
with no buttons, switches, knobs or 
levers to adjust or forget 

The ESF uses a miniature tape 
cartridge, about the size of a busi- 
ness card, called a wafer. The 
transport mechanism uses a direct 
drive motor with only one moving 
part Designed to read and write 



digital data only, the ESF suffers 
from none of the drawbacks of 
cassettes - without the expense of 
disks. 

Several versions of the ESF are 
available, for the TRS-80, Apple, 
PET, OSI and an RS 232 unit 
Even the slowest of the units is 15 
times faster than a cassette, and all 
are as reliable as disk drives - in 
fact a lot of users say they are more 
reliable! 




excellence in electronics 



exatron 



To get further information about 
the ESF give Exatron a call on 
their Hot Line 800-538 8559 
(inside California 408-737 71 1 1). 

If you can't wait any longer then 
take advantage of their 30 day 
money-back guarantee, you've 
nothing to lose but time! 

181 Commercial Street 
Sunnyvale, CA 94086 




TRS-W. Aoph aad PET an UadMawte of Tandy. ApcU ■ 

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Ai Hayes we I 
ond best Or planned obsolescent 
believe m taking the state of the art to the 
limit Our new Smartmodem. for exam- 
ple, is the most sophisticated 300-baud 
originate answer modem you can buy. 
And yet. it is perhaps the easiest-to 
modem ever 

RS-232C Compatible. Smartmodem 
lets any RS-232C compatible computer 
or terminal communicate by phone with 
other computers and time-sharing sys- 
tems located anywhere in North America 
You get full and half-duplex operation 
with both Touch-Tone' and pulse dialing. 

Auto-Answer Dial Repeat. 
Smartmodem can answer the phone, dial 
a number, receive and transmit data, and 
then hang up the phone- automatically' 
If desired. Smartmodem will even repeat 
the last command You can depend on 
Smartmodem for completely unattended 
operation 

Completely Programmable. 
Smartmodem can be controlled using 




■ g language. Over 30 dif- 
ferent commands can be written into your 
programs or entered directly from your 
keyboard 

Smartmodem also includes sever- 
al switch-selectable features that let you 
taiior performance to your exact needs. 
You can set it and forget it for the 
mate in convenience 

Built-in Audio Monitor. Thanks 
to an internal speaker, you can actually 
listen to your connection being made 
You II know immediately if the line is busy 
or if you reached a wrong number - 



and you don t even need a phone' 

Status at a Glance 
indical 

Direct-Connect Design. 

Smartmodem is FCC re 

jack- theres no aco> 
signal loss and disl 

Smartmodem. Smart Buy. 
fessional . 
formance 
A suggested retail pnce of only S279 

what more could you want"? Per- 
haps the matching Hayes Stack Chrono- 
graph, an RS-232C compatible calendar 
clock system 

Check out the Smartmoderr, 
ever fine computer products are sold 
And don t settle / y v 
for anything less I I |Uo\fac 
than Hayes 1 J J liCiyCO 

CIRCLE 153 ON READER SERVICE CARD 



Smartmodem. 
The ultimate concept in mode 
is now a reality. 





(404) 449-87^1 

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, 



ireotiue 
computing 
equipment 
evDluntion 



Apple Silentype and Graphic Writer 



CJje prince anb tJje^aper 



Keith E. Walker 



You pays your money and you takes 
your chances, they say, and sooner or 
later you*ll probably take your chances 
on a printer. This review will cover the 
Silentype printer by Apple Computer and 
a software package offered by Computer 
Station for this printer. The software 
package is also available for the Paper 
Tiger printers hooked up to an Apple II. 

The Silentype printer is offered by Apple 
Computer for the Apple II and the new 
Apple III computers. The printer comes 
with its own special interface card and 
one roll of paper, which by the way. comes 
in HO' rolls and is 8.5" wide. 

Now. I'm just a computer hacker who 
enjoys punching out totally incompre- 
hensible programs that only another hacker 
could love. But. deep in the heart of all 
hackers is a yearning to write THE program 
that everyone simply has to have. 

A printer may not help me become a 
better programmer, but it couldn't hurt. 
No more nights spent LISTing and LISTing 
and LISTing. Hard Copy! Just the sound 
of those words brings warmth to my 
heart. 

The main reason I wanted a printer 
was for programming, so a letter-quality 
printer wasn't necessary (or affordable) 
and indelible copy wasn't needed. So I 
chose the Silentype. It is the third printer 
in Apple's lineup and it retails for $625 
(or whatever you and your friendly mer- 
chant agree upon. Don't tell anyone, but 
I got mine for a lot less). 

The printer buzzes along at the breath- 
taking speed of 40 characters per second 
(top speed) and prints those letters in a 5 
x 7 dot matrix. The speed varies, though, 
with how dark the intensity is set. The 
darker the type, the slower the printing 
speed and vice versa. 

It handles the normal ASCII character 
set (without true descenders on lower case), 
and prints in both uni-directional and bi- 

Keilh E. Walker. 726 Mh Ave. So.. Apt A. Great 
I alls. MT 5940$. 



directional formats. The maximum line 
length is 84 characters with 10 characters 
to the inch. The Silentype has the standard 
six lines per inch vertical spacing. 

Completely devoid of any buttons or 
switches (inside or out), the only control 
on the printer is a typewriter-like platen 
feed. Just one little knob to worry about. 
All of the controls are handled with 
software or by directly accessing printer 
memory (via POKEs or control characters). 
This means never having to remove the 
cover to get at DIP switches. 

As for control characters, the Silentype 
recognizes LF and FF (line feed and form 
feed) but reacts a little differently to the 
form feed than one would expect. All the 
form feed does is issue a preset number 



THIS 


7 '■. 




'Cr- SC 


n~ 


GRAPHIC 


Vv'H I ~E=* 


IS 


R 


T'3:-:T 


en 


0'3R9HI0 


W9IT3Si 


rt-us 


is 


ft 


TEST 


□F 


GRPlPti k C 


kiFlTER 


THIS 


IS 


r9 


TEST 


OF 


GRAPHIC 


iJRZTtR 



of line feeds. With non-perforated roll 
type paper, a true form feed doesn't make 
much sense anyway. The operator can 
vary the number of line feeds it does by 
POKEing a certain address. 

The other control characters handle 
such features as graphics screen dump. 
printer/CRT mirroring (this limits the 
printer to 40 letters per line due to the 
Apple screen width) and a normal 80 
character width output. 

What about print quality and that 
doggone thermal paper? Well, print 
quality is as good as the the average impact 
printer and this printer won't wake up the 
cat. The name Silentype is very apt. If 
you drag a pencil eraser across this page 
you'll have just about the right level of 



p^incinG iCQP 
qaiMTikiO MiSflOfl 

PRINTING BVTE 



PRINTING SLfMT 






5ȣ 






F 



% 



3 3* 




! O 



4 



♦v. L / I 

) 



\ " 



\ 



; 






If 



L..-' 



AUGUST 1981 



17 



Silentype, continued. 



;>*+ , - . /@ 1 23456789 : ; < = >?@fiBCDEFGH I JKLMNOPQRSTUUHXYZ C "■•• 1 ■<-- '■ abc oef ?h 1 J k 1 mnop^rstuvwx* 
*+#-. /Z 1 23456789 1 $<* >?@ftBCOEFGH I JKLMNOPQRSTUUHXYZ [\ J>_ • abc def *h i J k 1 mnop^r stuvwxy z 
+ ,-.,"©! 23456789 1 *<■ >?eflBCDEFGH I JKLMNOPQRSTUUHXYZ C n 3 A _ ' abc def sh i J k i mnoF^rstuvwx*z< 
,-. /0 123456789: i<= >?efiBCDEFGHI JKLMNOPQRSTUUHXYZ [\ 3 •*_ abcdef *hi jk Imno^rstuvwxyzt I 
-. /8 1 23456789 : j<« >?6flBCDEFGH I JKLMNOPQRSTUUHXYZ C ■ ] *_ s abc def sh i Jk i nn©p*rstuvwxwz< ! > 
. - 8123456789: *<«>?enBCQ£F6M I JKLMNOPQRSTUUHXYZ C \ 3 'O abcdef ahi Jk ImnoP^rsUJVWXWZ* I > 
'••'8 1 23456789 : »<« >?6flBCDEFGH I JKLMNOPQRSTUUHXYZ [ \ 3 -_ '" abc dcf ah i J k 1 «noF«irstovwxyz< ' J 



noise. In other words, it is very, very 
quiet. 

Contrary to what you may have heard, 
the Silentype doesn't use that weird feeling, 
scratch prone, silver paper that thermal 
printers used to use, but a white paper 
that is almost indistinguishable from the 
real thing. 

While it is true that if you like to keep 
your paper in the oven or in the trunk of 
your car when you're not using it, the 
paper will turn black, but it just isn't as 
sensitive to heat as everyone makes it 
sound. The technology of paper seems to 
have kept pace with the rest of the 
microcomputer industry. 

I have many list-outs that are approach- 
ing their first birthday, and there is no 
deterioration . . . yet. Another difficulty 
is trying to get something resembling a 
standard size sheet of paper when you 
have to decide where to tear the sheet 
(no dotted lines here!). 

One more thing the Silentype doesn't 
offer is the extended type fonts (stretched 
out letters) that true impact printers offer. 
Those characters are great for headers 
and form printing. 

The graphics capabilities are about 
average for a modern printer, but you 
don't have to purchase special graphics 
software to use it. All that you have to do 



is press ctrl-Q. stand back and watch. If 
you don't mind a little inaccuracy the 
Silentype will do the graphics dump bi- 
directionally which is pretty quick, or for 
a better look, you can set the printer for 
uni -directional printing, which isn't very 
fast. 

Altogether, I'm very pleased with the 
Silentype printer, except for one very small 
detail. For those people lucky enough to 
own an Apple III computer, the Silentype 
can be programmed to print different fonts. 
Seems as though Apple could have at 
least offered that proper software for the 
Apple II. 

But, where there's a need, there's a 
programmer, and Computer Station in 
St. Louis, MO, offers software to accom- 
plish this feat. The only requirement for 
this software package is that you have 
DOS 3.3 and Apple DOS Tool Kit. Known 
as "Graphic Writer," it will print any of 
the fonts available in the DOS Took Kit 
(about 30 different ones), with the only 
limitation being that you can only print 
69 letters to the lines as opposed to the 
normal 80. But don't be alarmed, the char- 
acters still spread fully across the page. 
The routine is pretty easy to incorporate 
into your programs and is compatible with 
Apple Writer (in fact, it was designed for 
it). 



To include Graphic Writer in a program 
of your own. Computer Station has pro- 
vided an example program. It explains 
with RKMarks how to accomplish the task. 
All it involves is loading in the object 
code and your chosen character set and 
doing a few pokes to initialize the program. 
Computer Station didn't exactly go over- 
board in providing information on how 
the object code works, but then how many 
companies do? 

All in all. Graphic Writer has to be one 
of the best things that has happened to 
the Silentype. With it, you can print in 
anything from ASCII to Katakana 
(Japanese characters), or even special 
graphics characters. And as a plus you 
now get true descenders on your lower 
case letters. Quite an impressive package. 

To sum things up. I am very pleased 
with the Silentype printer, especially in 
combination with the Graphic Writer 
package from Computer Station. While 
it's true that my print-outs will get a tan if 
1 leave them out in the sun for too long, 
this is a small problem to overcome. The 
print quality is good, the speed isn't bad 
and it /.\ quiet. Graphic dumps are as easy 
as pie with control from within a program 
fairly easy to accomplish. 

I'll give it an 85, it's got a good beat and 
it's easy to dance to. □ 



C omJuting 



Chas Andres 




18 



CREATIVE COMPUTING 



The BEST games are from Creative Computing Software 

1978: Adventure 

1979: Air Traffic Controller 

1980: Super Invader 

1981: Blister Ball 
and Mad Bomber 



Blister Ball 



Blister Ball is the first completely original 
arcade-type game for a computer. Not a 
copy, not an adaptation, not a spinoff. Blister 
Ball is new— it's a new idea— better than 
Invaders, better than Circus, better than 
Asteroids, better than Galaxian. If you ve 
played other games for hours, you'll play 
Blister Ball for days. 




How does it work? Well, some mean but 
fun-loving aliens have produced some 
bouncing bombs. First they drop one and 
you ve got to position yourself under it and 
zap it with your laser. If you miss, that's 
OK. It will bounce around, although each 
bounce is lower, and you have several 
chances to zap it. Got the hang of it? OK. 
here come two bouncing bombs. You zap 
them. Then you're faced with three, then 
four and five. 

As they bounce longer and longer the 
walls begin to close in so you re faced with 
either zapping the bombs or being hit. Each 
hit knocks you a little further toward the 
gutter. But you can survive two hits which 
is usually enough to zap all the bombs. 



Feeling confident? Don t. Because after 
5 bombs the murderous little devils drop 5 
bonus bombs, worth ten times as much. 
These don t bounce, so you get only one 
shot. You need nerves of steel and the 
reflexes of a tail gunner. 

After you complete one round .the game 
starts again with bombs that bounce faster 
and lower (and are worth more) than the 
previous ones. 

Blister Ball is a fantastic solo game. But 
there are two-player options as well in which 
players can play as a team or as opponents. 
Each player can move the entire width of 
the screen and zap any of the bombs. Here, 
you re not only trying to survive, but trying 
to outscore your opponent. The game has 
two skill levels. 

Mad Bomber 

In Mad Bomber you are faced with aliens 
in a huge ship hovering overhead. They 
have bomb racks which they constantly fill 
with bombs. Your object is to move from 
side to side on the ground and zap the 
bombs in the bomb racks or as they fall. 




As the game progresses, the aliens fill 
up their bomb racks more quickly and the 
bombs fall faster. You lose after ten bombs 
have hit the area which you are defending. 

Mad Bomber can be played by one player 
solo or by two players as a team or as 
opponents. Two skill levels. 

Order Today 

Blister Ball and Mad Bomber are available 
together for $29.95 on disk (DOS 3 2) only 
and require a 48K Apple with paddle 
controls. (We recommend using the Super 
Paddles from Peripherals Plus). 

To order send $29 95 plus $2.00 shipping 
and handling to the address below. Credit 
card customers should include card number 
and expiration date of Visa. MasterCard or 
American Express card. Credit card orders 
may also be called in to our toll-free number 
in the continental U.S. 

If you also wish to order a set of Super 
Paddles from our Peripherals Plus subsidiary, 
the cost is just $39.95. The paddles are 
backed by a 90-day limited warranty from 
the manufacturer as well as Peripherals 
Plus moneyback guarantee of satisfac- 
tion. 

Blister Ball and Mad Bomber are colorful, 
challenging, fast and noisy They are the 
games of the year from Sensational Soft- 
ware 

creative 
computing 



39 E. Hanover Avenue 

Morris Plains. NJ 07950 

Toll-free 800-631 -«1 12 

In N J 201-540-0445 



J 



AUGUST 1981 



CIRCLE 300 0N READER SERVICE CARD 



Hi-Res Cribbage 




for More 



Dale Archibald 



creative computing 
SOFTWARE PROFILE 

Name: Hi-Res Cribbage 

Type: Cardgame 

System: 48K. Apple II or II Plus and 

one disk drive. DOS 3.2 

and 3.3 
Formal: Graphics 
Language: Maehine 

Summary: Spare-time diversion for 

avid eribbage fans 
Price: $24.95 

Manufacturer: 
On-Line Systems 
36575 Mudge Ranch Rd. 
Coarsegold.CA93614 



The Hi-Res Cribbage game designed 
by Warren Schwader for On-Line Systems 
has fine graphics and plays a mean hand. 
For a beginner, it would be a good way to 
learn. An expert might want to practice 
cribbage skills with various hands. 

The program deals two hands of six 
cards. It lays the player's hand face up. 
You select which two cards you want to 
place in the crib (discard pile for a later 
count). When you've done so. the computer 
discards two and play begins. 

For non-cribbage players, let me explain 
that one object during the play of the 
hand is to play a card that brings the 
running total to 15 or 31. This earns points 
for the player and advances the peg the 
correct number on the well-drawn cribbage 
board. (The noise made as the peg is 





. 




II 1 1 








-A- 

CHOOSE 2 CARDS TO 
— PUT IN THE CRIB 

— — — I 2 3 4 c 




Ml ■ ■ 

ESS \m •'•• h :: H ■ ■— :: 1 







On-Line Cribbage. 



Dale Archibald. INI7 Thinl Ave. N.. Minneapolis, 
MN 55405. 



20 



advanced gets a bit irritating. I felt.) Other 
scoring configurations, such as pairs, 
triplets, or a run, also advance the peg. 
Once all cards from the hand have been 
played, the program outlines the scoring 
combinations held in the hand. 

A jack and a five, for instance, totals 15 
and receives two points. Two jacks and a 
five earn two points twice, and two for 
the pair. The program lists the number of 
pairs, fifteens, etc.. and advances the peg 
the correct number. After both hands 
have been played, the program totals the 
points in the crib and advances the peg 
for them. 

The beginner's game holds the list of 
combinations and points received quite a 
long time to allow the novice to see how 
the sums are arrived at. For an intermediate 
cribbage player such as I. they were held 
much too long. 

The advanced game, on the other hand, 
plays much too fast, and sweeps the played 
cards away so rapidly that there's almost 
no chance to see what was played. ..and 
I'm a speed reader. 

A game may be saved in mid-play if 
you have a disk prepared by Hi-Res 
Cribbage. I'd like to take this opportunity 
to complain about this practice; why do 
so many software publishers demand a 
disk initialized by each particular program? 
It means a blank disk saved just for that 
particular game or whatever, and I'm 
unwilling to spend that much money just 
to save one unfinished item. Why can't 
they do as Strategic Simulations does? 
You can save their games on any initialized 
disk. 

Be that as it may. this is a good cribbage 
learning tool, and the instruction book is 
very clear and explanatory. If you're in 
need of an everready partner here 'tis. □ 

CREATIVE COMPUTING 



An In telligentA Iter native 




In the research you are doing before purchas 
ing your computer printer, you are probably con 
fused by the various claims, speeds, choices, 
shapes and prices Well, we'd like to clear the air 
a bit and tell you about the most unusual comput 
er printer around — the TYPRINTER 221. 

You see. it's unusual because it is totally 
compatible with every computer and word proces 
sing program from the largest to the smallest 
It's versatile to the point of incredibility We'll 
discuss the broad advantages and explain the 
details 



THE DAISY WHEEL 

The special daisy wheel supplied is of a unique 
design consisting of a 1 00 character carrying radii. 
Each radii is formed of two distinct types of 
plastic — an "elastic plastic" for the stalk of the 
radii, and a comparatively "hard plastic" used to 
form the character area This, combined with a 
very narrow character profile and a special posi 
tioner on each of the 100 radii, guarantees a 
uniform character density There is near perfect 
geometric positioning of the character with no 
character higher or lower than the others And 
because of its unique dual material design, micro 
vibrations have virtually been eliminated, leaving 
your final copy clean, clear and smudge free The 
copy produced is comparable to that produced by 
metal daisy wheels and at a fraction of the cost 



KMWMCTO* 



ujttTewcnw* 




THE KEYBOARD 

The keyboard has been referred to as a triumph of 
human engineering - from the way the keys seem 
to have been custom designed to fit your fingers, 
to the way the special feature switches have been 
grouped A flip of a switch (or under computer 
control of course) and the. printer becomes a 
foreign language machine Push a button, and like 
magic the printer automatically locates and lines 
up columns of figures, perfectly balanced between 
the margins This incredibly fast, extraordinarily 
quiet electronic keyboard puts more programming 
power at you fingertips then printers costing five 
to ten times as much 



TYPRINTER 221 



THE DISPLAY 

The TYPRINTER 221 presents a new dimension in 
operator/machine communications In the manual 
(typewriter) mode, the printer controls and verifies 
all entries before printing The display exhibits the 
last 1 5 characters of the text, word-by word, until 
the end of the line The operator may control what 
will be printed before the actual printing takes 
place This new found flexibility enables you to 
make modifications along the entire line and in 
both directions This 20 character plasma display 
has the ability to scroll backwards as well as 
forwards, will give the operator a visual indication 
as to which print mode is currently being selected 
as well as the number of characters remaining 
before the right margin is reached The display will 
also indicate to the operator 

The number ol cheiaclets a»ailable What chaiactets will be mseiled 

■ the memo<» "» •" e>.sting leu 

When the P'inlei 'S ■ en «"»' *"*'" '"* m emof» '" "* P"" " 1 

condition 'me nas been selected 

When a pie piogiommod totm lev A warning message that the end ot 

out has been selected the page is being apptoeched 

When the pcmtet is opeieting from That a hyphenation decision must be 

the internal memofv made 

PRINT MODE 

The TYPRINTER 221 will allow you to automatic- 
ally highlight individual characters, words or 
complete sentences Whatever is entered from 
the keyboard or from the computer, even an 
existing text file, can be printed in one or more 
of the five different modes 
traditional printing, 
underlined characters: 
true bold characters where the horizontal 
component of the character is increased 
without disturbing the vertical com- 
ponent: 
characters which are both bold and under- 
lined, and: 
a feature unique among computer printers 
printing in reverse — white on black, 
sort of reverse video on paper 



THE FEATURES 

Automatic justification of the right margin 

The electronics of the TYPRINTER 221 have made 
right hand justification a simple, automatic 
operation 

Phrase and format storage 

Phrases dates, addresses, data, etc that 

may be stored in your computer's mem 

ory may be sent over to the printer and 

stored in one of the "memory bins" of the 

printer. This information may then be used by the 

operator in the manual mode This can save you 

hours when trying to get a form "just right " 

Automatic centering 

The TYPRINTER 221 will not only center any title 
between the preset margins, but will also center 
over one or more columns, or over any specific 
point and will even align copy with the right 
margin independent of the left margin 
Automatic vertical lines 

A command from the computer enables an auto- 
matic feature which prints vertical lines at any 
point on the paper. 
Automatic tab sequence recall 
With the TYPRINTER 22 1 you may store and recall 
the most frequently needed margin and tab 
sequences for applications such as daily corres- 
pondence, statistical reports, etc This guarantees 
consistent high quality appearance of each 
document 
Paragraph indent 

A computer command instantly sets a temporary 
margin in order to print one or more indented 
paragraphs with respect to the right margin. 
Automatic decimal point location 
No matter how many figures to either the left or 
right of the decimal point, the TYPRINTER 221 
will automatically line up the figures with the 
decimal point in any position you choose 
Statistical printing has never been easier. 
Column layout 

This feature allows you to obtain automatic and 
perfect distribution of spaces between columns in 
respect to the margins A perfect page balance is 
assured without the need to carry out calculations 
or additional operations 

There is a wide variety of options that you can 
add to TYPRINTER 221. 

By now you are probably convinced that we 
are sold on our machine, and we hope you can 
understand why In fact, why don't you use these 
facts to measure against any and/or all the other 
computer printers on the market 

When you do. you will realize the TYPRINTER 
221 is an intelligent electronic typewriter, a text 
formatter — and a brilliant computer printer — 
available at a suggested list price of only $2850 
TYPRINTER 221 is available at your local 
computer shop — or we'll tell you where you can 
see and try one if you call us at 



MULTILINGUAL CAPABILITY 

A unique and useful leature ol the TYPRINTER 22 1 
is its capability of being able to print in several 
languages without changing the daisy wheel 
In addition to English, every standard daisy wheel 
has the ability and the necessary characters to 
print in French. Spanish, Italian and German 
CIRCLE 190 ON READER SERVICE CARD 



tf 



HOWARD 
INDUSTRIES 



2051 E CERRITOS AVE , 8C 

ANAHEIM. CA 92806 

714/778-3443 




I vcr since Bruce Wallace wrote the 
Apple version of Asteroids in Space 
(available from Quality Software), new 

versions of asteroids have appeared with 
startling regularity. At least four versions 
were sent to us in the past year. None was 
reviewed since none was .is good as the 

original Wallace program. Now. a new 
asteroids game has appeared. Expecting 
vet another rehash. I was pleasantly 
surprised with the program. While Apple- 
Olds, from California Paeifie. is basically 
another version of the familiar arcade 
game, the program has nice touches and 
additions that make it worth owning. 

The most obvious change is the use of 
floating apples ithe fruit, not the computer) 
instead of asteroids. The apples, when 
shot, break up into smaller apples, and 
these smaller apples break up further when 
Int. You start out with six large apples. 
Clear them and you get a field of eight. 
I ach successive field has ten apples. 

I here are two enemy ships that can 
appear with alarming frequency. The large 
ship shoots in a pattern rather than aiming 
for you. Destroying this ship earns you 
200 points. The small ship goes for blood 
and is worth 1000 points. The point values 
ol the apples vary according to size. Vou 



start with three ships, ami win an extra 
ship for each 10.000 points 

So far. this all seems lairly standard. 
But there is more. One of the problems 
with Asteroids is the method of controlling 
the ship. Apple-Olds seems to have taken 
a fairly sensible approach. Caddie number 
I controls rotation of the ship. The button 
on that paddle controls thrust. The ship 
will keep going after you release- the button, 
but it will also decelerate and stop after a 
while Firing is controlled from the key- 
board. Anv kev from to 9 fires a shot. 



creative computing 
SOFTWARE PROFILE 

Name: Apple-oids 

Type: Arcade game 

System: 32K Apple. Disk Drive 

Format: Disk 

Language: Machine Language 

Summary: Fun to play 

Price: $29.95 

Manufacturer: 

California Pacific Computer Co. 

7700 Edgewater Dr. 

Oakland. CA 94621 



Any other key puts you in hyperspace 
I here is a chance that the ship will explode 
on emergence from hyperspace. I here is 
also a chance of emerging from hyperspace 
right on an asteroid. Such occurences are 
fatal. 

I he ship rotates smoothly with a turn 
ol the paddle When the paddle isat either 
extreme, it sends the ship into a continuous 
spin. This avoids the problem encountered 
when the paddle is fully turned anil vou 
want to continue rotating. 

The game displays the score and high 
score in hires numbers on the side of the 
screen. The number of ships remaining is 
represented pictorial!) at the bottom. 

As a bonus, the disk also contains 
( hipout, which, as you've surelv guessed, 
is a version of breakout. Done in hi-res. 
the program will satisfy breakout tans. 
I here is one very nice touch. Vou start 
out with five balls They are stored in a 
horizontal slot on the left wall Each time 
a new ball comes into play, it slides from 
the slot, moves across the screen, then 
drops. 

Simply put. Apple-oids is very gix>d. 

I he game is fun. highly replayable. and 

excellent graphically. California Pacific 

ime out with another winner. f~] 






22 



CREATIVE COMPUTING 




The business information 
you need at the turn 
of a key. 

Datadex is a new 
interactive business 
management system 
designed for the Apple 
personal computer. It's from 
IUS, the people who brought you 
EasyWriter ,M and who are bringing you 
new products for office automation, 
education, and development systems. 

Datadex is short for data index. It lets you 
put all your business data into your Apple 
the way you like to see it and manipulate it 
any way you want. It adapts to your way 
of doing business. 

Want to generate a sales report? Just press 
four keys and fill in the blanks. That puts 
your sales data into the computer. Now, 
your report: Datadex designs it for you, 
based on what you've entered. Nothing to 
it. That's power! 

You can do the same with phone lists, 
mailing lists, dealer names or inventories. 



They all enter Datadex and form your own 
personal data base. 

Want to find a company but don't know 
how to spell its name? Try something that 
sounds close, and our Soundex routine will 
find it. It is very forgiving on typos and 
extra spaces. 




POT 



• :» 



OATAl 
IN YOUR 
APPLE. 



Soundex helped us find Mr. 
Zukrzawski when we were 
balancing our checkbook. 
We weren 'I sure how to spell 
Als name, so searched for 
AlZ and found him. 
Instantly. The check register 
and several other applica- 
tions are free with Datadex. 



JM 



Want a specific piece of information, like 
sales for January 14-21? Inquire Datadex 
and the answer comes up on the screen 
right now. And right. 

Want a report of all sales in ZIP code areas 
starting with 9? Sure. Just ask it to print a 
report. 

But seeing is the only way to believe. Get a 
demonstration of Datadex at your local 
Apple dealer. See the personal computing 
power it can bring to your office and home. 
If you've looked at a VisiCalc-type program, 
see Datadex before you buy. 

By the way, about IUS. We're the Apple 
of software. We got there by giving you 
great products and super support. We 
provide customer service over the phone. 
Professionally written documentation. 
And products that are never outdated, 
only updated. Information Unlimited 
Software, Incorporated, 

281 Arlington Ave. , Berkeley, 
CA 94707. (415) 525-9452. 



* * 








Does your other software have 
auto system configuration and 
auto report generation? 
Datadex does. You don't 
have to be a computer 
expert to get results! 






f P^ 



> 



if., 




wmm m m w 



<« ' — i? 



nil IMI .mtHl'.MIItmiMIIII ItilUlllllHI IIMllll' 




Datadex it a trademark of Sonoma Softworks. 
EasyWriler is a trademark of Cap'n Software. 
Apple ij a trademark of Apple Computer Inc. 
VisiCak is a trademark of Personal Software. Inc. 



CIRCLE 151 ON READER SERVICE CARD 







2ftf 



*;■« 



*•* .•■.; T'^vf? 






- '■••?:■ 

:• wSfl 






A Program to Write Programs in Basic 



The Last One 




creative computing 
SOFTWARE PROFILE 

Name: The Last One 
Type: Programming Tool 

System: 4KK Apple. CBM, Atari. 

TRS-HO. OSI. Sharp 
Formal: Disk 
Language: Creates Basic programs 

Summary: Potentially great, but 
unproven 

Price: $600 (Tentative) 

Manufacturer: D. J. "AI" Systems Ltd. 
Station Road. 
Ilminster 
Somerset. England 



This program, currently running in 
prototype form on Ohio Scientific C-3 
computers, writes computer programs in 
Basic. Its name. The Last One." is meant 
to imply that human beings will no longer 
have to write programs. I fear that the 
authors are excessively optimistic, but the 
program does work, and is a significant 
advance in programming. 

The operator answers questions from 
menus presented on the computer screen. 



1 Open Files 1—2 

2 Jump to end of file 2 

3 Set index to start of file 1 

4 Console input using labels from file 2 

5 Ask user "Is this data correct". If no jump 

6 Search file 1 for data 

I i«urc I. Sample Pwudo Code. 



Then the program translates the answers 
to these questions into pseudocode as in 
the figure. Finally, the pseudocode is 
compiled into a standard Basic program. 
The program is well commented, with 
the pseudocode listed in remark statements 
when memory allows. Since the finished 
product is in ordinary Basic, it can be 
edited and modified. 

The demonstration of the prototype was 
under controlled conditions, with all 
operation by the author of the program 
and no opportunity for lesser mortals to 
try it. This would make it easy for the 
author to avoid problems the program 
couldn't handle. Despite this, it was easy 
to see that The Last One could be a 
significant aid in rapidly developing an 
error free Basic program. 

At least in the current implementation, 
the program requires a programmer to 
operate it. It is necessary to anticipate 
the file structure and organize the develop- 



ment of the program in a logical order. 
While this requires skill and planning, it is 
much faster than typing the code by hand, 
and no debugging time seemed to be neces- 
sary. 

The principals of the firm, David James 
(the programmer) and Scotty' Bambury. 
anticipate having the program ready by 
late summer. Versions are planned for 
( )hio Scientific. Apple, Atari. TRS-80, PET 
and Sharp computer systems, with a 
projected price of $600. James and 
Bambury expect eventually to extend The 
Last One to program in other languages, 
with Cobol to be implemented next. 

No graphics abilities were demonstrated, 
and it is likely to be a long time before 
clever graphics programmers become 
obsolete. The logical conclusion is that 
The Last One is useful primarily for 
straightforward business and computational 
applications. This reviewer feels that many 
such applications can probably be done 
faster, better, and easier with VisiCalc. 
making it unnecessary to write a program 
in the first place. Because The Last One 
generates Basic code, it necessarily shares 
the limitations of Basic, including slow 
speed, somewhat clumsy structure, and 
inefficient use of memory. 

Creative Computing will publish an in- 
depth review when a version is ready for 
release. fj 






24 



CREATIVE COMPUTING 




YOU'LL 







Say goodbye to the costs and 
frustrations associated with writing software: 
The Last One " will be available very soon 

More comprehensive and advanced 
than anything else in existence, 
The Last One " is a computer program that 
writes computer programs. Programs that 
work first time, every time. 

By asking you questions in genuinely 
plain English about what you want your 
program to do, The Last One" uses those 
answers to generate a totally bug-free 
program in BASIC, ready to put to 
immediate use. 

What's more, with The Last One," 
you can change or modify your programs as 
often as you wish Without effort, fuss or any 
additional cost. So as your requirements 
change, your programs can too. 



In fact, it's the end of programming 
as you know it. 

And if, because of the difficulties and 
costs of buying, writing and customising 
software, you've put off purchasing a 
computer system up to now, you need delay 
no longer. 

The Last One" will be available very 
soon from better computer outlets. To place 
your order, take this ad into your local 
dealer and ask him for further details. Or in 
case of difficulty, please write to us direct. 



» 



THEL4ST0NE 



YOU'LL NEVER NEED BUY ANOTHER PROGRAM. 

D.J. 'AT Systems Ltd., Ilminster, Somerset, TA19 9BQ. England 

Telephone: 04605-4117. Telex: 46338 ANYTYR G. 

CIRCLE 134 ON READER SERVICE CARD 



AUGUST 1981 



25 



creatine 




usic Maker Module 

• • • • ^ # 



• ; . peep in tl)e Heart of Texas 



Owen Linderholm 



From deep in the heart of Texas comes 
the Music Module, a plug-in module for 
the Tl 99/4 which gives it limited music- 
synthesis capability. No fancy sixteen voice, 
waveform controlled or stereo output 
machine, the module provides only three 
music voices, some volume control and a 
little bit of noise generation. 

Sound-Graphs 

Two modes are available: "sound-graphs" 
and "traditional." the first is used mainly 
as a strange noise maker. When you enter 
this mode you are asked which noise 
generator you want, what speed at which 
to play the music and whether you want 
to change any of the frequencies for the 
scales. There are eight noise generators 
available, four of which provide "periodic" 
noise and four of which provide "white" 
noise. One generator from each of these 
two groups plays noise based on the 
frequency of the third musical voice. When 
I was experimenting with these generators. 
1 found that they added very little to the 
sound produced. Of the speeds available, 
only those between about 1 5 and 30 were 
of much use. as those lower than 15 were 
far too slow to play the music in a 
recognizable manner. 

The ability to change frequencies is of 
some use, but since the sound-graph mode 
cannot produce much of musical value 
this feature is not very useful. 

When these values have been set. the 
computer proceeds to the music input 
mode. The user is shown two rectangular 
areas in which he can draw lines which 
represent various frequencies, volumes and 
noises. Inputting a measure can be done 
with the keyboard or the Wired Remote 



Controllers. I found the keyboard very 
awkward to use and could only input 
exactly what I wanted with difficulty. 

Editing of the music already entered 
can be easy or difficult depending on how 
much needs to be changed and on where 
and when the mistake is discovered. One 
very useful editing facility is the ability to 
copy all or part of a measure already 
entered. Playback of the music is relatively 
simple and pleasant effects are obtainable 
with a little effort. The longest composition 
can only be 46 measures, which is generally 
long enough for most purposes but can 
be annoying if a longer piece is desired. 




Traditional Mode 

The other mode available is the tradi- 
tional mode by which music can be entered 
in standard musical notation. The method 
of input is similar to the method for sound- 
graphs. When you enter the traditional 
mode, you are asked to enter the number 
of sharps or flats to define the key signature, 
then the time signature and the speed. All 
these are necessary and work as they 
should, except for the speed which is 



exactly the same here as for the sound- 
graphs. 

The method of entering music is also 
the same except that when you wish to 
change between different types of note, 
such as between crotchets or quavers, 
the cursor must be moved from the staff 
off to the side, where the notes can be 
changed. This involves a great deal of 
key pushing and frustration, and makes 
the entry of most pieces of music a very 
laborious task. 

The staff and the rest of the screen 
display is very well laid out and the music- 
is easy to read with the three different 
voices shown in three separate colors. 
Another feature is that each note can 
have independent volume control on a 
scale of one to eight. This allows crescendos 
and decrescendos and so on. but is also a 
bit difficult to use. 

Editing and playback are similar to the 
sound-graph mode and are reasonably 
straightforward. Music can be easily stored 
on cassette or disk and retrieved. It is 
also possible to print out music if the TI 
thermal printer is connected. These are 
very useful functions and not available on 
many more expensive and complicated 
computer music synthesizers. The other 
major disadvantage of the module is its 
three-octave range. 

Now comes the great advantage of the 
Music Maker Module: the extremely low 
price of $40. At that price, the Music 
Module is a worthwhile investment for 
the average user who is not thinking of 
recording contracts or playing at major 
concert halls. It is also quite possible that 
using the remote controllers makes the 
entry of music a lot simpler. D 






26 



CREATIVE COMPUTING 



Software for the Apple II and Apple II Plus 1 



BENEATH APPLE DOS 

A Technical Manual 
By Don Worth and Pieter Lechnef 
Become an expert on the intricacies ol Apple's DOS (Disk Operating System) BENEATH 
APPIE DOS is the perfect companion to Apple's DOS 3 3 Manual Containing eight 
chapters, three appendices, a glossary, an index, and over 160 pages, this manual will 
serve to completely till in the many gaps lett by Apples DOS 3 3 Manual Written tor 
Apple users with DOS 3 3. 3 2 or earlier versions, any Apple disk user would welcome 
having this carefully written manual at his fingertips 
LEARN 

• How DOS 3 3 differs from other DOS versions 

• How disks are protected 

• How to reconstruct a damaged diskette CATALOG 

• How tracks are formatted 

• How to use the disk directly, without DOS 

• How to call DOS's file manager 

• How every routine in DOS works 

• How to customize DOS to your needs 

• How to overcome DISK I/O ERRORS 

• About the "secret" file types — S and R 

INCLUDES 

• Large quantities ol excellent diagrams and tables 

• Source listings ol uselul disk utilities 

• Glossary of over 150 technical terms 

• Exhaustive description of DOS program logic 

• Handy reference card 

• Useful patches to DOS 

• Many programming examples 

Book $19 95 



CROSS REF by Jim Aafto 

Applesoft programmers will be delighted to have this cross reference utility program in 

their tool kit' ol software aids What can CROSS REF do to speed and facilitate your 

Applesoft program development' Consider these functions 
VARIABLE CROSS REFERENCE LINE CROSS REFERENCE 

FIND VARIABLE FIND LINE NUMBER 

REPLACE VARIABLE VARIABLE ONLY LISTING 

LINE ONLY LISTING 

Features that make CROSS REF easy to use include 

• Written in machine language, occupies less than 3K 

• Resides passively in memory while DOS or Applesoft is active 

• Can be loaded with your Applesoft program already resident 

• Very fast — a VARIABLE CROSS REFERENCE tor a 16K Applesoft program can start 
printing in 5 seconds 

• Contains printer format controls and headers lor documentation 

• Prints English language error messages 

Cassette $22 95 Diskette $24 95 



L 

I 

N 
K 
E 
R 



LINKER by Don Worth 

Turn your Apple II or Apple II Plus into a powerful and productive 
software development machine with this superb linking loader/editor 
package LINKER does the following and much more: 

• Dynamically loads and relocates suitably prepared machine 
language programs anywhere in RAM 

• Combines a mam program with subroutines You can assemble a 
subroutine once and then use it with as many main programs as you 
wish 

• Produces a map ot all loaded routines, giving their location and the 
total length of the resulting module 

• Contains a library of subroutines including binary multiplication and 
division, print text strings, delay, tone generator, and random 
number generator 

Linker works with virtually any assembler for the Apple II Requires 32K 
of RAM and one disk drive 

Diskette $49 95 
Manual Only • $19 95 




Cassette 



FASTGAMMON" By Bob Christiansen 
Sound, hi res. color, and musical cartoons have 
helped make this the most popular backgammon 
playing game for the Apple II But don't let these 
entertaining features fool you — FASTGAMMON 
plays serious backgammon Runs on any Apple II 
with at least 24K of RAM 
$19 95 Diskette - $24 95 



,'<r 



METEOROIDS IN SPACE" 

By Bruce Wallace 

We have taken our popular space 

game, formerly called Asteroids in 

Space, and made some important im 

provements To accent these improve 

ments we have given it a new name — 

METEOROIDS IN SPACE Your space 

ship travels through a shower ol 

deadly meleoroids ltyourshipishit.il 

will be destroyed, so you use your laser 

gun to blast the meteoroids Big 

meteoroids shatter into smaller 

meteoroids when hit. and the smaller 

ones are usually faster and lust as 

deadly From time to time you will en 

counter an alien space ship whose 

mission is to destroy you. so you'd 

better destroy it first All the action is 

displayed in fast, smooth, high resolu 

tion graphics, accompanied by sound effects You now can control your ship using one 

of two options — the Apple game paddles or the keyboard One ol the game paddle 

buttons controls the laser fire In METEOROIDS IN SPACE, the spaceship's velocity 

gradually decreases unless more thrust is applied, adding an element of control Also 

new to this version is a hyperspace feature — translate instantly to another spot in the 

galaxy The game is over when five of your ships have been destroyed An additional 

ship is added lor every 1 0.000 points you score Runs on any Apple 1 1 wit h at least 32K 

of RAM and one disk drive 

Diskette $19 95 




<£** 



ASTROAPPLE" by Bob Male 
Your Apple computer becomes your astrologer, 
generating horoscopes and forecasts based on the 
computed positions of the heavenly bodies This 
program offers a delightful and stimulating way to 
entertain friends ASTROAPPLE produces natal 
horoscopes (birth charts) tor each person based 
on his or her birth data Any two people may be 
compared for physical, emotional, and intellectual 
compatibility The program is written in Applesoft 
BASIC with machine language subroutines It 
requires either RAM or ROM Applesoft and at least 
32K of memory 

Cassette $14 95 Diskitti $19 95 





FRACAS" by Stuart Smith 

A fantastic adventure game like no other 1 Up to eight 
players can participate in FRACAS at the same time 
Journey in the land ot FAROPH. searching for hidden 
treasure while warding oil all sorts ot unfriendly and 
dangerous creatures You and your friends can compete 
with each other or you can join lorces and gang up on the 
monsters Your location is presented graphically and sound 
effects enliven the battles Save your adventure on diskette 
or cassette and continue it at some other time Both integer 
BASIC and Applesoft versions included Requires at least 
32K of RAM 



Cassette $19 95 Diskette $24 95 



BATTLESHIP COMMANDER" by Erik Kilk and Matthew Jew 



A game of strategy You and the computer each start out by positioning five ships of 
different sizes on a ten by ten grid Then the shooting starts Place your volleys skillfully 
— a combination of logic and luck are required to beat the computer Cartoons show 
the ships sinking and announce the winner Sound effects and flashing lights also add 
to the enioyment of the game Both Applesoft and integer BASIC versions are included 
Requires at least 32K of RAM 

Cassette - $14 95 Diskette $19 95 



Also by Don Worth 

BENEATH APPLE MANOR - Adventure Uses Integer BASIC 

Cassette $14 95 Diskette $19 95 
BABBLE Fun with words, sound, and graphics 

Cassette $19 95 Diskette $24 95 



rgTS QUTiLny softwtjrg 

^V^^fcj 6660 Reseda Blvd Suite 105. Reseda. CA 91335 

Vflb*i (213)344-6599 

Now exclusive distributors tor products from The Software Factory. Newhall. California 
'Apple II and Apple II Plus tit trade marks ol Apple Computer Inc 



WHERE TO GET IT: Call us at (213) 344-6599 for the name of the Quality Software 
dealer nearest you If necessary you may order directly from us Mastercard and 
Visa cardholders may place orders by telephone Or mail your check or bankcard 
number to Quality Software. 6660 Reseda Blvd. Suite 105. Reseda. CA 91335 
California residents add 6% sales tax SHIPPING CHARGES Within North America 
orders must include $1 50 for first class shipping and handling Outside North 
America the charge for airmail shipping and handling is $5 00 Pay in US 



currency 



CIRCLE 195 ON READER SERVICE CARD 



New Products Abound 



The National Computer 
Conference 



Betsy Staples 



As I begin this article, my word processor 
is flanked by 6" stacks of literature describ- 
ing the new products introduced at the 
National Computer Conference. 

On the top of the pile, the unquestioned 
leader of the pack, sits the literature on 
the Xerox Star, "a personal information 
system for business professionals that 
combines text editing, graphics creation 
and communications." 

The system consists of a Xerox 8000 
NS processor, large size CRT screen, 
keyboard, disk files and hand-operated 
pointing device called a "mouse" as well 
as an internal controller and cable con- 
nector for tapping in to the Xerox Ethernet 
network. 

Perhaps the most stunning features of 
the Star are its graphics and typesetting 
capabilities. In addition to the standard 
word and data processing functions you 
would expect to find on a $16,000 com- 
puter, the Star has graphic facilities which 
enable the user to: draw a line on the 
screen using the mouse; enlarge or reduce 
graphics; shade and texture rectangles; 
join objects in a cluster; split a cluster 
into several objects; and maintain a library 
of user-defined graphic symbols. 

The Star also has the ability to display 
a full two pages of typeset material exactly 
as it will appear when printed-out. Each 
Star font can consist of over 65,000 different 
characters. Thus, a single type font could 
include small caps, accented characters, 
Greek characters, math symbols, data 
processing symbols, etc. 

The only catch is that the only output 
device capable of doing justice to these 
graphics and typesetting features is the 
$30,000, 12 page per minute, Xerox 8044 
electronic printer. 



Electronic mail is another area in which 
the Star shines. When connected to the 
Ethernet network, incoming mail is 
depicted on the screen as a letter in the 
user's in-basket. Any Star document, folder 
or record file can be "mailed" as is to any 
number of local and remote network 
users. 

Software options to be offered by Xerox 
include a package to create complex 
mathematical equations in correct typeset 
fashion; a program to check spelling; 
advanced graphics packages which allow 
the user to construct automatically table- 




The Xerox Star stole the show. 

driven bar charts, pie charts and bar graphs; 
and communications software to enable 
Star to communicate with non-Xerox work- 
stations. 

Rumor has it that by the time you 
read this, Xerox will have introduced a 
"stripped down" version of the Star in the 
$60CK) price range. We'll let you know as 
soon as we have more information. 



Familiar Faces 

Ohio Scientific introduced IBS-NET. a 
distributed processing computer and local 
network system with advanced communica- 
tions capability. Designed for small busi- 
nesses, individual departments within larger 
companies, and remote branch offices, 
the system places microprocessor-based 
work stations at each key desk in an office 
and connects them to central disk files, 
printers and remote communications 
channels. 

A very practical feature of the system 
is that the end user can start with a stand 
alone computer system, and as his business 
grows, add terminals for a time sharing 
system which can ultimately be networked 
under IBS-NET, Ohio Scientific, 1333 
Chillicothe Rd., Aurora, OH 44202. 

Atari announced price reductions for 
several of its products. The 16K Atari 400 
will now retail for $399. Prices of the 8K 
and 16K RAM Memory Modules for the 
Atari 800 are now $49.95 and $99.95 
respectively, and the Atari 82040-column 
impact printer has been reduced to 
$299.95. 

New software available for the Atari 
800 includes Personal Financial Manage- 
ment System, a database-oriented system 
designed to help the user plan and analyze 
a home budget ($74.95); Dow Jones Invest- 
ment Evaluator, which connects the com- 
puter to the Dow Jones Information Service 
($99.95); and Microsoft Basic for the 800 
($89.95). 

Atari Sorcim Macro Assembler and 
Program-Text Editor, both designed for 
use by advanced programmers, were 
announced with price and availablility as 
yet undetermined. Atari Inc.. 1265 Borregas 
Ave.. Sunnyvale, CA 94086. 



28 



CREATIVE COMPUTING 



IT'S TIME TO GRADUATE FROM BASIC 

If you're serious about programming you know 
that assembly language is a tool that you must 
master. 

What you may not realize is that, because of 
you BASIC experience, you already know a great 
deal about assembly language. 

If you want to get the feel of assembly 
language programming without getting the whole 
6502 machine manual crammed down your throat 
we have the book for you. ASSEMBLY 
LANGUAGE PROGRAMMING FOR THE APPLE® 
BASIC USER will get you into 6502 assembly 
language by paralleling it with your BASIC ex- 
perience. When you finish this book you will be 
convinced that assembly language programming 
is not nearly as difficult as you have been led to 
think, and that YOU can do it. And the best part is 
that the book is only $9.95. All you have to do is 
fill in the coupon and send it in with check or 
money order for $9.95 

AND THEN... 

if you like what you find in ASSEMBLY 
LANGUAGE PROGRAMMING FOR THE APPLE® 
BASIC USER, you'll find a coupon in the back that 
is good for $3.00 off the price of our big assembly 
language book, PRACTICAL MICROCOMPUTER 
PROGRAMMING: THE 6502, or any of our other 
publications on the Z80, 8080 or 6800. The big 
book comes with a coupon for a FREE 
editor/assembler system. That's right, FREE. 

WHEN HAVE YOU SEEN AN OFFER THIS GOOD BEFORE? 



ASSEMBtf 



PKOGRABOBIW 



B8BB 



ASSEMBLY LANGUAGE PROGRAMMING FOR THE APPLE' BASIC USER 



Send coupon and check or money order to: 

Northern Technology Books 
Box 62 
Evanston, IL 60204 

□ Check for $9.95 enclosed 



□ Money Order for $9.95 enclosed 



Name 



Address 



City 



State 



Zip 



Checks must be in US dollars payable on a US bank. 
Illinois residents add 6% sales tax. 



Apple is a Registered Trademark of Apple Computer, Inc.. Cupertino CA. 
AUGUST 1981 29 



Commodore was again showing the 
VIC20. which, it appears, they are actually 
ready to ship this time. 

Scheduled for delivery by Commodore 
in late 1981 is the Micro-Mainframe, a 
computer based on the CBM Model 8032 
which features an integrated green 
phosphor 12" (80 x 25) display. 73-key 
typewriter style keyboard with upper and 
lower case, numeric keypad and full cursor 
control. 

The Micro-Mainframe is a psuedo 16- 
bit, 6809-based system with 36K ROM. 
%K user RAM and 2K screen RAM, and 
supports most CBM peripherals. 

It can operate as a stand alone system, 
as a mainframe system development tool 
using available languages and up-load/off- 
load capabilities, and for training in 
language and system design. A software 
package, designed by Waterloo Com- 
puting Systems Limited, includes inter- 
preters for Waterloo MicroBasic. Micro- 
Pascal. MicroFortran and MicroAPL; a 
text editor; operating system; and assembly 
language development system. Commo- 
dore. 300 Valley Forge Square. 681 Moore 
Rd.. King of Prussia. PA 19406. 

From the Orient 

Most of the Japanese firms, being 
relatively new to the computer industry 
were relegated to basement level of 
McCormick Place. Their new products 
were aimed squarely at the business 
market. 

Toshiba was showing the T200/T250 
computer system, which consists of a 
keyboard; monitor, CPU and disk drive 

the Toshiba T2S0. 




unit; and 136-column. 125 cps. dot matrix 
printer. The 64K machine features 10 user- 
programmable function keys and Microsoft 
Basic-80 running under CP/M. The T200 
is available with one or two 5 1/4" disk 
drives; the T250 with one or two 8" drives. 
Toshiba Corporation, Tokyo, Japan. 

Sony introduced the Typecorder, a 
"letter size," portable, electronic typewriter, 
dictator, transcriber and communicator. 
The battery-powered unit has a 40- 
character, single line display which allows 
typed text to be edited before transmission 
and/or print out. 

It contains a microcassette. which can 
be used for dictation/transcription or 
storage of up to 100 pages of text. Available 
options include the Compact Printer. Office 
Printer, Electric Typewriter Actuator. 
Acoustic Coupler Transmitter, Telex Tape 
Puncher and Communication/Printer Inter- 
face. 




i ■ ■ ■ ET 



The Sony Typecorder. 

Also new from Sony is the Series 35 
"total word processing system" which 
features a built-in microcassette recorder 
for dictation and full page CRT display. 
Text may be stored on dual high density 
3.5" micro floppy disks. The Series 35 is 
compatible with the Typecorder. Sony. 
Office Products Division. 9 West 57th St., 
New York, NY 10019. 

Sharp Electronics announced the Sharp 
YX-3200. a desktop system with 32K ROM 
and 64K RAM expandable to 72K and 
128K respectively. It can accommodate 
up to eight dual-sided, double density, 5 
1/4" disk drives. 

CP/M compatible, the system features 
an Automatic Program Generator which 
allows the user to create programs by 
answering a series of simple questions. 
Business applications software is also avail- 
able. 




A high-resolution. 12" CRT display 
featuring upper and lower case characters 
on an 80 x 24 screen, and a bi-direction, 
dot matrix, 80 cps printer round out the 
system, which carries a retail price under 
$6,000. 

The Sharp PC-1211 Pocket Computer, 
also introduced at NCC, boasts 1.9K of 
RAM programmable through the keyboard. 
Optional cassette interfaces and printer 
provide increased storage capacity and 
hard copy. 




"...and it will also slice, dice, and make french fries. ' 



TheSharpPC-1211. 

The Pocket Computer can handle Basic- 
programs of up to 70 lines. The display is 
a 24-character, dot matrix LCD panel. 
The suggested retail price of $249.95 
includes three manuals. Sharp Electronics 
Corporation. 10 Keystone PI., Paramus. 
NJ 07652. 

Several of the desk top computers being 
shown by Canon reflected their calculator 
ancestry. The TX-10, TX-15 and TX-25 
look more like desktop calculators with 
letters on their keys than computers. All 
are 6809-based with IK of RAM. The 
TX-10/15 has 8K of ROM and the TX-25 
has I6K of ROM and a micro-floppy disk 
cassette. 

The TX series has an alphanumeric 
fluorescent tube display of 20 or 26 
characters and a 26 character per line, 
dot matrix printer. Programming may be 
done in Basic or Assembler. The TX- 
10/15 sells for about $1300. and the TX- 
25 for $2295. 

The Canon CX-1 is a desktop computer 
that looks like a computer with its 12 (80 
x 24) CRT display, mini-floppy disk drives 
and full size printer. It offers 32K of user 
RAM and storage capacity of 320K if two 
double density, double-sided disk drives 
are used. Retail price of the CX-1 is 
$4995. 

In addition to the Basic and Assembler 
languages included with the system, the 
Modular Business Accounting software 
provides seven interactive applications: 
sales order processing, accounts receivable, 
accounts payable, inventory, payroll, job 
cost and general ledger. The MBA 
packages retail for about $600 each. Canon 
USA, Inc.. One Canon Plaza, Lake Success. 
NY 11042. 



30 






CREATIVE COMPUTING 



3t*C 



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MIC 



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I 

i 
I 



NEW COLLEGE BOARDS 



for TRS-80 
81/82 PET, APPLE™ 



The best way to sharpen your skills for the College Boards is to work on actual examinations. Each of 
these program sets confronts the user with a virtually limitless series of questions and answers. Each 
program is based on past exams and presents material of the same level of difficulty and in the same 
form used in the College Board examination. Scoring is provided in accordance with the formula 
used by College Boards. 

SAT, PSAT, N.M.S.Q.T., set includes 20 programs covering Vocabulary, Word Relationships, Reading 
Comprehension, Sentence Completion, and Mathematics. Price $149.95 

EDUCATOR EDITION - SAT, PSAT includes all of the above programs plus detailed solutions and 
explanations for each problem plus drill exercises. SAT set includes 26 programs $229.95 

GRADUATE RECORD EXAMINATION set includes 23 programs covering Vocabulary, Word Relation- 
ships, Reading Comprehension, Sentence Completion, Mathematics, Logical Diagrams, Analytical 
Reasoning. $199.95 

EDUCATOR EDITION - Graduate Record Exam Set includes 33 programs. $289.95 

Owners of our initial College Board series can upgrade their package to the College Board 81-82 specs, 
including the all new reading comprehension, sentence completion plus expanded vocabulary and 
mathematics sections for $69.95. 

''{I ALL TIME SUPER STAR BASEBALL 
& SUPER STAR BASEBALL 



i 




All TIME 

SUPERSTAR BASEBALL 

Sample Linkup 



T. Williams 
|. Foxx 

H. Greenberg 
R. Hornsby 
H.Wilson 
B.Terry 
M Mantle 
H. Aaron 
W. lohnson-p 



SUPER STAR BASEBALL 
Sample Lineup 



D. Parker 
W Stargell 
W.Mays 
P. Rose 
O. Cepeda 



I.Rice 
H. Aaron 
L. Brock 
R. Carevv 
H Killebrew 



C. Yazstremski R. Allen 

W. McCoyey R Leflore 

R. lackson R.Zisk 

C. Brett B. Madlock 

R.Cuidry-P T. Seaver-p 



Performance is based on the interaction of 
actual batting and pitching data. Came can 
be played by one or two players with the 
computer acting as a second player when de- 
sired. Players select rosters and lineups and 
exercise strategic choices including hit and 
run, base stealing, pinch hitting, intentional 
walk, etc. Highly realistic, there are two ver- 
sions, ALL TIME SUPER STAR BASEBALL, and 
SUPER STAR BASEBALL featuring players of 
the present decade. Each includes about 50 
players allowing nearly an infinite number of 
roster and lineup possibilities. 

•Both Games $24.95 



SWORD OF ZEDEK 

Fight to overthrow Ra, The Master of Evil. In this incredible 
adventure game, you must confront a host of creatures, nat- 
ural and supernatural. To liberate the Kingdom, alliances 
must be forged and treasures sought. Treachery, deceit and 
witchcraft must be faced in your struggles as you encounter 
wolves, dwarves, elves, dragons, bears, owls, ores, giant bats, 
trolls, etc. Each of the twelve treasures will enhance your 
power, by making you invisible, invulnerable, more elo- 
quent, more skillful in combat, etc., etc., as you explore the 
realms of geography, both on the surface and underground. 
Dungeons, temples, castles, mountains, etc., are all a part of 
the fantastic world of Ra. Each game is unique in this spec- 
tacular and complex world of fantasy. $24.95 



II 




f 1/ // S TIME TRAVELER 

t/ff J y% The best of the adventure games. Confronts player with 
— .- /^'-^r complex decision situations and the demand for real timeac- 
it ^fc_r: tion. Using the Time Machine, players must face a challeng- 
^ jjQL. *C.~^T ' n 8 series of environments that include; The Athens of Per- 
^TKt^ aM^^sTX ic ' es - Imperial Rome. Nebuchadnezzar's Babylon, Ikhnaton's 
j/yMSSS^- i; ~* Egypt, lerusalem at the time of the crucifixion. The Crusades, 
'B* la* • ^ Machiavelli's Italy, the French Revolution, the American Rev- 
olution, and the English Civil War. Deal with Hitler's Third 
Reich, Vikings, etc. At the start of each game players may 
choose a level of difficulty. . .the more difficult, the greater 
_th<> time pressure. To succeed you must build alliances and 
3 struggle with the ruling powers. Each game is unique. 

$24.95 



I 

L 




ISAAC NEWTON 

Perhaps the most fascinating and valu- 
able educational game ever devised - ISAAC 
NEWTON challenges the players (1-4) to 
assemble evidence and discern the under- 
lying "Laws of Nature" that have produced 
this evidence. ISAAC NEWTON is an induc- 
tive game that allows players to intervene 
actively by proposing experiments to deter- 
mine if new data conform to the "Laws of 
Nature" in question. Players may set the 
level of difficulty from simple to fiendishly 
complex. 

In a classroom setting the instructor may 
elect to choose "Laws of Nature" in accor- 
dance with the complete instruction man- 
ual provided. 

For insight into some of the basic principles 
underlying ISAAC NEWTON see Code!, 
Fschvr. fij( h by Douglas R. Hofstadter. 
Chapter XIX and Martin Gardner's "Mathe- 
matical Games" column in Scientific Amer- 
ican, October, 1977 and |une, 1959. 

$24.95 



I 



♦ALL PROGRAMS AVAILABLE FOR 

TRS-80, APPLE II & PET 
•Programs for APPLE or TRS-80 are on 
D disk or D cassette, please specify. 

All prognmi require 1 6K* FRS-GO programs require L[V(L II BASIC* APPLE programs require Applesoft BASIC 



• Kfell Software 

Send check or money order to \ 



Send check or money order to 
21 Milbrook Drive, Stony Brook, NY 1 1790 

(516) 751-5139 



CIRCLE 219 ON READER SERVICE CARD 



The Canon TX-2S. 










The Canon LBP-10 laser primer looks more like a copier lhan a primer. 



Other Entries 

Vector Graphic unveiled a shared pro- 
cessor system which allows five workers 
in the same office to perform word and 
data processing via individual video display 
terminals. Known as the 5005 Multi-Share 
System, the computer is Z80-based and 
uses a 5M, 5 1/4" Winchester disk, a 
630K floppy disk and an error-correcting 
disk controller. 

Software provided with the Vector 5005 
includes the CP/M-2 operating system. 
Scope editor. Raid debugger. ZSM 
assembler and Microsoft Basic-80. Options 
are Peachtree business accounting office 
software, and the Memorite III word 
processing and ExecuPlan financial plan- 
ning packages. The system with a single 
terminal is priced at $8995; additional 
terminals are $1895 each. Vector Graphic 
Inc., 31364 Via Colinas, Westlake Village, 
CA 91362. 

Intertec Data Systems also announced 
a multi-user, shared disk computer system. 
Each CompuStar Multi-User System 
consists of a network of up to 255 daisy- 
chained video display terminals, each of 
which employs its own internal micro- 
processor and dynamic RAM. 

A CompuStar system can be configured 
using a 10M Winchester-type drive or a 
32M or 96M Control Data Corporation 
Cartridge Module Drive with a 16M 



a CompuStar constellation. 




removable, top-loading platter and either 
16M or 80M or fixed disk storage. Further 
flexibility is available through a choice of 
four types of Video Processing Units. 
Intertec Data Systems, 2300 Broad River 
Rd.. Columbia, SC 29210. 

The Chieftain 98W30 from Smoke Signal 
Broadcasting is configured around the 6809 
microprocessor and has 32K or RAM 
expandable to 1M. 

In addition to a 30M 8" Winchester 
disk drive, the 98W30 supports an 8" floppy 
disk drive for 1M of back-up storage and 
offers a 20M tape streamer option. 

Software available for the system 
includes the OS-9 Level I and Level II 
multi-user, multi-tasking operating system. 
The Chieftain 98W30 sells for $9995. 
Smoke Signal Broadcasting, 31336 Via 
Colinas. Westlake Village, CA 91362. 

Symbiotic Systems announced the 
Stratos computer system, a Z80A-based 
computer with 80K of dynamic RAM and 
1.2M of on-line disk storage enclosed in a 
custom teak wood cabinet. 




The Strains computer system. 



Among the software included with the 
Stratos are a built-in ROM Monitor, CP/M 
2.2, the Spellbinder word processing text 
editor and office management system, a 
choice of either ( 'Basic or Pascal compiler, 
a full financial package, and a program to 
create new character sets with a light 
pen. Symbiotic Systems, 118 Naglee Ave., 
Santa Cruz, CA 95060. 



"For the exercise of intelligence, on 
invention and discovery, a man must have 
some surplus materials, time, and energy, 
at his personal disposal, with freedom to 
seek whatever employment he prefers. " 
Isabel Paterson 



Print It! 

A recurring theme throughout the exhibit 
area was the new and ever trickier printer. 
Everyone was emphasizing print quality 
and graphics capabilities. 

At the top of the heap here were the 
laser printers which look like office copiers 
and produce original copies. Probably 
because they look like copiers, they seem 
slow, but when you remember that the 
real comparison is to be made with other 
letter-quality printers. 10 pages per minute 
doesn't seem so bad. 

The Canon LBP-10. an OEM product, 
uses plain paper and offers vertical or 
horizontal print selection. A font selection 
feature allows the user to print using 
proportional spacing or boldface type. 
Optional interfaces include 8-bit parallel 
and RS-232C serial. LBP Department, 
Canon USA, One Canon Plaza, Lake 
Success. NY 1 1042. 

The Imprint- 10, based on the Canon 
LBP-10, is a xerographic intelligent printer 
system which uses software definable fonts 
to print justified text in a variety of styles 
and sizes. It also prints on plain paper 
and comes with a standard RS-232 inter- 
face. Pricing on the Imprint-10 is "in the 
upper $20,000 range." Imagen, 12769 
Dianne Dr., Los Altos Hills, CA 94022. 

Another printer making use of advanced 
technology was the AI650, an ink -jet printer 
from Anderson Jacobson Inc. Character 
width and spacing are variable and can 
be switched from 80 characters per line 
to a compressed 132 characters per line. 
Under computer control, it will print 
extended characters, boldface and upper 
and lower case in any combination at a 
speed of 180 or 210 cps. A disposable ink 
cartridge supplies ink to the print head. 
Price of the AJ650 is $3500. Anderson 
Jacobson Inc., 521 Charcot Ave., San Jose, 
CA 95131. 

Dot Matrix Printers 

Based on the print quality being delivered 
by many of the dot matrix printers at 
NCC, we can no longer draw a line between 
dot matrix and letter-quality printers 

The Toshiba TH-2100H. for exam 
is a dot matrix printer with a 24 thin-wire 



'een 

pie, 
vire I 



32 



CREATIVE COMPUTING 




The next generation 
of business software 



WHAT'S IN A NAME? 

■ 
symbol 

■ 
become conf; 

Our ne-- 

■ 
Lord of the f?mgs 01 
used to • 

chang* 
yOu' I 

WORD PROCESSING 
We know m 
Designer So'' 
compc 

■ 

■ 
packages you 

■ ■ 

■ 



ACCOUNTING 

■ . 

. rograms hove be< 

■ 

ompleted or scheduled (or cor* . 
Fixed A 
■ 

i'AtANTIR'" 

■ 

■ 
■ 



"Designer Software" 

HOUSTON 



* -ig can do lor your 

ulion. 



3400 Montrose Blvd • Suite 718 • Houston, Texas 77006 
(713)520-8221 • Telex 790510 • Source TCU671 



CIRCLE 150 ON READER SERVICE CARD 



NCC, continued... 

head whose print quality is all but unidentifi- 
able as dot matrix. It features proportional 
spacing and graphics, and prints at 100 
cps for word processing and 160 cps for 
data processing. The TH-2100H is currently 

100 CPS FOR WORD PROCE 

160 CPS FOR DATA PROCES 
24xN FOR WORD PROCESSI 

Prim sample: Toshiba TH-2100H. 

available only to OEMs at a price under 
$2000. Toshiba America. Inc., OEM Divi- 
sion, 2900 MacArthur Blvd., Northbrook. 
IL 60062. 

Okidata introduced the Microline 83 at 
the top of its office printer line. Faster 
than its sibling, the 83 prints bidirectionally 
at 120 cps. It produces 136 columns on 
15" wide forms at the standard 10 cpi 
spacing and will also print condensed 
characters to provide up to 132 columns 
on narrower forms. Centronics parallel 
and RS-232C serial interfaces are standard. 
Okidata Corporation, 111 Gaither Dr.. 
Mt. Laurel. NJ 08054. 

Epson America was showing the MX- 
80FT, a tractor and friction feed dot matrix 
printer which features expanded, con- 
densed, condensed/expanded, double-strike 
and emphasized printing modes. It also 

!l*'()*+,-./0 
1234567B0:;=?A 

uwmwmm 

P'aMffgfftjklmti 

opqrstuumxljH 

These decorative characters were venerated by 
Sam '76 software on an Apple with ZHO card 
running under CP/M. and printed on an Epson 
MX-H0. Other fonts are also available. 



allows the user to switch between fanfold 
and single sheet paper by flicking a lever. 
Epson America, Inc., 23844 Hawthorne 
Blvd., Torrance, CA 90505. 

Centronics introduced the Model 739 
which prints 7x8 dot matrix characters 
with true underline at 10 and 16.5 char- 
acters per inch for data processing tasks 
and generates N x 9 proportional characters 
with true descenders for text editing. 




PRESEN 




12345678 16 12 
SOLUTION r.Rp + ]XCOH"] ALW 
IN CONDENSED NODE AT 16.7 CHARACTERS 

Print sample: Centronics 739. 

Available with either parallel or serial 
interface, the 739 also has graphics capa- 
bilities and is priced under $1000. Cen- 
tronics Data Computer Corp.. Hudson, 
NH 03051. 

The Model WP6000 Words Plus printer 
from Anadex prints 150 cps in cor- 
respondence mode and 500 cps in rough 
draft or data processing mode. Multiple 
resident character fonts, as well as optional 
downloading of other fonts from a host 
computer, are provided along with propor- 
tional spacing, text justification, and the 
ability to print superscripts and subscripts. 

lO point BERIPA character 
OPQR8TUVWXY2 .bedefghi 

*•()»♦.--/»»<->? • t>j*_ttr 

■in*[V(4x a ))-log„(2y')+4s''18 

Print sample: Anadex VVP6000. 

Available during the fourth quarter of 
1981, the WP6000 will sell to OEMs for 
$1800. Anadex Inc., 9825 DeSoto Ave., 
Chatsworth,CA91311. 

MPI announced the 99 Omega, a 100 
cps graphics printer which provides an 1 1 
x 9 font for correspondence and a 7 x 7 
font for data processing, which can be 
selected in either 80. % or 132 column 
modes. In addition to standard fan fold 
paper, single sheets may be used. The 99 
Omega lists for $899. 

Wide Carriages 

MPI also announced the Model MP 150, 
a wider, faster version of the 99 Omega 
which prints up to 226 columns at 150 
cps. The MPI 50 retails for $1095. MPI, 
4426 South Century Blvd., Salt Lake City, 
UT 84107. 

Another wide-carriage, dot matrix printer 
was introduced by DIP, Inc. The DIP-132 
is a 132-column printer which features 9 x 
9 or 1 1 x 9 characters, six character sizes, 
1 10 cps bidirectional printing and graphics 
capability. The printer, priced at $995, 
can handle single or multi-part forms 
ranging from 1.5" to 15" wide. DIP, Inc., 
745 Atlantic Ave., Boston, MA 021 1 1. 

Narrow Carriage 

The Alphacom Sprinter 40 is a 40-column 
thermal printer which noiselessly prints 
four lines per second. Characters are 



formed in a 5 x 7 dot matrix and have 
slight descenders. Optional cables and 
adapters allow the user to interface the 
printer to most popular personal and 
business computers. Alphacom, Inc., 2323 
So. Bascom Ave., Campbell. CA 95008. 

Tiny Teleprinter 

The Qwint KSR-743. weighing less than 
12 lbs. and smaller than a portable type- 
writer, is a full-feature keyboard printing 
terminal with RS-232 and current loop 
interfaces standard. The KSR-744 is a 
keyboard teleprinter with an internal 103- 
style modem, and the RO-743 is a receive- 
only printer. 




The Qwint KSR-743. 

Print speed is over 50 cps and com- 
munication speed is selectable over the 
range of 110 to 1200 baud. Qwint tele- 
printers also support a graphics mode and 
provide backspace and forward and reverse 
half line spacing for printing superscripts, 
subscripts and underlining. Qwint Systems, 
Inc.. 3693 Commercial Ave.. Northbrook. 
IL 60062. 

Colored Tiger 

The IDS Color Printer is the newest 
member of the Paper Tiger family of dot 
matrix printers. Features include text 
justification, proportional spacing, pro- 
grammable tabbing, bidirectional printing 

Print sample: IDS Color Printer. 




M&. 



THE PAPER TIGER 
MING IN _; = 



34 



CREATIVE COMPUTING 



The Text Solution for APPLE II® 

Now APPLE II® Owners Can Solve Text Problems 

With VIDEOTERM 80 Column by 24 Line Video Display 

Utilizing 7 X 9 Dot Character Matrix 

Perhaps the most annoying shortcoming of the Apple II* is its limitation of displaying only 40 columns by 24 lines of 
text all in uppercase. At last, Apple 11* owners have a reliable, trouble-free answer to their text display problem. 
VIDEOTERM generates a full 80 columns by 24 lines of text, in upper and lower case. Twice the number of characters as 
the standard Apple II* display. And by utilizing a 7 by 9 character matrix, lower case letters have true descenders. But 
this is only the start. 



VIDEOTERM, MANUAL. 
SWITCHPLATE 




VIDEOTERM 



» $ X t ' t * , - . I 
B123456789: ;<■>» 

(ABCDEFGHI JKLHNO 

r u v u x y z i 

'abtoffohiik lino 



7X12 MATRIX 
18X80 OPTIONAL 



I l 11 < 5 i 7 B J : ! < « »,' 

MICCf f iH I J unto 
■«IS Til VUX Y Z I \ 1 t _ 

■ i b : t t ' 3 ► ' . ' • ' c 
pqrstuvwiyll ! )"l 



Advanced 
Hardware 
Design 



Available 
Options 



BASICS VIDEOTERM lists BASIC programs, both Integer and Applesoll. using the entire 80 
columns Without splitting keywords Full editing capabilities are otlered using the 
ESCape Key sequences for cursor movement With provision tor stop/start text 
scrolling utilizing the standard Control S entry And simultaneous on screen display 
ol text being printed. 

Pascal Installation ol VIDEOTERM in slot 3 provides Pascal immediate control ol the 

display since Pascal recognizes the board as a standard video display terminal and 
treats it as such No changes are needed to Pascals MISC INFO or GOTOXY tiles, 
although customization directions are provided All cursor control characters are 
identical to standard Pascal defaults 

Other The new Microsoft Soltcard' is supported So is the popular D C Hayes Micro- 

Boards modem II" . utilizing customized PROM firmware available from VIDEX The power 

lul EasyWnter Professional Word Processing System and other word processors 
are now compatible with VIDEOTERM Or use the Mountain Hardware ROMWritef 
(or other PROM programmer) to generate your own custom character sets Natural, 
ly. VIDEOTERM contorms to all Apple OEM guidelines, assurance that you will have 
no conflicts with current or tuture Apple II expansion boards 

VIDEOTERM s on board asynchronous crystal clock ensures llickertree character display 
Only the size ol the Pascal Language card. VIDEOTERM utilizes CMOS and low power con- 
sumption ICs ensuring cool, reliable operation All ICs are fully socketed tor easy 
maintenance Add to that 2K of on board RAM. 50 or 60 Hz operation, and provision ol power 
and input connectors for a light pen. Problems are designed out. not in 

The entire display may be altered to inverse video, displaying black characters on a white 
held PROMs containing alternate character sets and graphic symbols are available Irom 
Videx A switchplate option allows you to use the same video monitor lor either the 
VIDEOTERM or the standard Apple If display, instantly changing displays by flipping a 
single toggle switch The switchplate assembly inserts into one ot the rear cut outs in the 
Apple If case so that the toggle switch is readily accessible And the Videx KEYBOARD 
ENHANCER can be installed, allowing upper and lower case character entry directly Irom 
your Apple If keyboard 

IK ol onboard ROM lirmware controls all operation of the VIDEOTERM No machine 
language patches are needed for normal VIDEOTERM use 
Firmware Version 2.0 



Characters 7x9 matrix 
Options 7x12 matrix option. 

Alternate user definable 
character set option; 
Inverse video option 



Display 24 x 80 (full descenders) 

18 x 80 (7 x 12 matrix with full descenders) 



Want to know more'' Contact your local Apple dealer today lor a demonstration VIDEOTERM is available 
through your local dealer or direct Irom Videx in Corvallis. Oregon Or send for the VIDEOTERM Owners 
Reference Manual and deduct the amount it you decide to purchase Upgrade your Apple If to lull terminal 
capabilities lor halt the cost of a terminal VIDEOTERM At last 



7X9 MATRIX 
24X80 STANDARD 



Apple If i» a trademark ot Apple Compute* Inc 
ROMWMfK* •» * trademarK of Mount*" Hardware inc 
Mvcromodem II" la a trademark ot C Mayes Associate* toe 

Soiicavrr •» a trademark ot Microsoft 

EMyWfitef is a trademark ot Inlormalioo Unlimited Software Inc 



PRICE: •VIDEOTERM includes manual $345 

• SWITCHPLATE $ 19 

• MANUAL relund with purchase % 19 

• 7 x 12 CHARACTER SET $ 39 

• MICROMODEM FIRMWARE $ 25 



APPLE II® OWNERS! 

introducing the 

KEYBOARD & DISPLAY 

ENHANCER 

■ PUT THE SHIFT AND SHIFT LOCK BACK WHERE IT BELONGS 
■ SEE REAL UPPER AND lower CASE ON THE SCREEN 
• ACCESS ALL YOUR KEYBOARD ASCII CHARACTERS 



VicWx has the perfect companion tor youj 
word processor software the KEYBOARD 
AND DISPLAY ENHANCER Install the 
enhancer in your APPLE II and be typing in 
lower case )usl like a typewriter If you want an 
upper caw character use the SHIFT key or the 
CTRL key for shift k>ck Not only that, but you 
see upper and lower case on the screen as you 
type Perfectly compatible with Apple Water 
and other word processors like, for example. 
Super Text 

H you want to program in BASIC . )ust put it 
back into the alpha lock mode, and you have 
the original keyboard back with a few im 



provements Now you can enter those elusive 4 
characters directly from the keyboard, or re 
quire the Control key to be pressed with the 
RESET to prevent accidental resets 

KEYBOARD AND DISPLAY 
ENHANCER is recommended for use with all 
revisions of the APPLE II It includes b ICs. and 
LPROM and dip switches mounted on a PC 
board, and a jumper cable Easy installation. 
meaning no soldenng or cutting traces Alter 
nate default modes are dip switch selectable 
You can even remap the keyboard, selecting an 
alternate character set. for custom applications 




PRICE»KDE-700<REV.7o*9rea««) »129. 

• KDE-000 (REV. 6 or lew) »lt». 

Apple II* is a trademark of Apple Computer. Inc 



I! 



idex 



VIDEX 
897 N.W. Grant Avenue 
Corvallis. Oregon 97330 
Phone (503) 758-0521 



CIRCLE 240 ON READER SERVICE CARD 



NCC, continued... 

with logic-seeking, forms control and a 
high resolution graphics option. 

IDS also introduced the product that 
wins our award for the best name at the 
show. Tiger Trax is a mylar, pin-fed page 
carrier that allows users to print on single 
sheets of paper using the Paper Tiger 460 
and 560 printers. Tiger Trax comes in 
two sizes to accommodate 8 1/2" x 11" or 
21cm x 30cm paper. Both sizes cost $16.95. 
Integral Data Systems. Inc.. Milford. NH 
03055. 

Dataproducts announced the M-100 
Matrix Printer. To demonstrate the 
graphics capabilities of the printer Data- 
products had artist Saul Berstein drawing 
portraits on an Apple Graphics Tablet 
and printing them out on the M-100. Some 
of the ones we saw were quite good, but 
that was probably a greater credit to 
Bernstein than to the printer. 




V: 




6 




Portrait of ■ publisher by Saul Bernstein and (he 
Dataproducts M-100. 

In addition to its ability to print very 
high resolution graphics, the M-100 can 
print superscripts, subscripts, true under- 
lines, and lower case letters with descenders 
at the rate of 140 cps. An 8-bit parallel 
interface is standard, and RS-232, current 
loop and Centronics interfaces are optional. 



The M-100 sells for $2995. Dataproducts 
Corporation. 6200 Canoga Ave.. Woodland 
Hills. CA 91365. 

Daisy Wheel Printers 

Alphacom also announced a daisy wheel 
printer-the DP2000-which sells for 
$1595. Features include programmable 
print parameters; incremental horizontal 
spacing and tabulation to 1/120 of an 
inch: horizontal and vertical tabbing 
functions; right and center justification 
of text; bidirectional friction feed platen; 
10, 12 or 15 cpi or proportional spacing; 
and standard 8-bit parallel interface with 



PnogAammable p/iint paA.ameteA'i 
4uch a-4 majigi/14, tab *top-i, 
boldface painting., {Lawn 

length, automatic underline , 
and oveM.4tA.ike. chaA.acteA.4 

Incremental hoaigontal 

spacing and tabulation io 
1/120 of an inch 

Ho a ijon / a t and vem 

tabbing {.unction* 

Prim sample: Alphacom DP2000. 

optional RS-232 interface. Print speed is 
20 cps. Alphacom. Inc., 2323 So. Bascom 
Ave.. Campbell, CA 95008. 

While not exactly a daisy wheel printer, 
the Converter TP121 allows the user to 
connect an Olivetti ET121 electronic 
typewriter to a computer. Connecting the 
converter requires no soldering or modifica- 
tion to the typewriter. Available interfaces 
include RS-232C serial, parallel and IEEE. 




The Olivetti typewriter retails for $595 
and the converter for $295. Vertical Data 
Systems Inc., 1215 Meyerside Dr., Unit 
2A. Mississauga, Ontario, Canada, L5T - 
H3. 

Touching and Talking 

Among the more interesting new prod- 
ucts at NCC were a touch-sensitive terminal 
and a talking terminal. 

The Dialogue Touchterm 80 introduced 
by Ampex responds to the user's touch 
on its screen. The specifications state that 
practical stylus sizes range from a pencil 
eraser or finger to a gloved hand. 

The user can either draw on a blank 
screen with his "stylus" or use it to select 
options from a menu printed on the screen. 




I he Dialogue Tochterm NO. 



For example, the demonstration running 
in the Ampex booth was designed to help 
a show goer select a restaurant in the 
Chicago area. After choosing (by touch) 
a general type of restaurant, the weary 
NCCer could choose (by touching its name 
on a list) an eating place about which he 
wanted more information. 

Possible applications for touch input 
include bilingual communication, order 
entry, industrial switching, security systems, 
computer aided instruction, and other tasks 
where touching is more reliable than typing. 
Ampex Corporation. 200 North Nash St., 
El Segundo, CA 90245. 

When hearing is more reliable than sight, 
the Votrax Type-V-Talk synthesizer can 
be used. The computer can either speak 
the words as they are typed or wait until 
the user requests them. Using the synthe- 
sizer, a computer can orally take a user 
through a complex routine, prompting him 
through a financial or accounting process, 
for example. 

Used as a teaching aid, it can tell students 
when and why they have answered a 
question or performed a function correctly. 
The possibilities for use in game software 
are limited only by the imagination of the 
programmer. Type-n'-Talk sells for $345. 
Vodex— A Votrax Company, 500 Stephen- 
son Highway. Troy, MI 48084. D 



36 



CREATIVE COMPUTING 



WE'VE CREATED 
A WORLD 
JUST FOR 

OSGORTH! It is a wonder | ^J ^J # 

world of swords-and-sorcery 

adventure to serve as your personal playground. 

THE SHATTERED ALLIANCE™, first in a line of 
forthcoming games from SSI that comprise the 
Chronicles of Osgorth. is a sophisticated strategy 
simulation centered on this rich fantasy 
planet and its ethereal trappings: magic, 
rivalry between realms, war among 
exotic creatures. 

With the multitude of armies 
either preassembled or designed by 
you, you can conjure up limitless 
scenarios — even the unlikely con- 
frontation of Osgorthian forces 
against Alexander the Great's Com- 
panions or Caesar's Legionnaires! 

Ah, the possibilities! 

THE APPLE COMPUTER paints in 
beautiful, color Hi-Res graphics a 
Osgorthian battlefield of knolls, mountains, 
forests, and open plains. Unit types are catego 

As part of our demanding standard* of excellence, 
we use ITI3XBII floppy discs. 




rized into five classes of infantry and four of cavalry. The tribes 

that populate this world are as varied as they are enchanted: 

dwarves, unicorns, amazons, centaurs — just to name a few. 

Your fantasy soldiers have been carefully rated for armor, 

speed, strength, and morale. Their weapons may be the bow. 

javelin, rocks, spears, pikes, swords, axes, clubs, or cavalry 

lance. ...and of course, spells that can magically enhance a 

unit's speed, defense, attacking power, or courage. 

AS RICHLY DETAILED as this game is, it never 
becomes unwieldly because the computer keeps 
track of everything. Its simple but elegant 
movement system was designed so that 
all action can proceed at a brisk pace. It 
also comes with a powerful and intelli- 
gent computer opponent for solitaire play. 
THE SHATTERED ALLIANCE is fun, 
fast, and easy to play — geared to incite 
your imagination. It comes with the 
game program disc (for a 48K Apple II 
with ROM card and a mini floppy 
disc drive), a rulebook, and four 
player-aid charts. For $59.95,get this 
fantastic piece of real estate today! 
To order with your VISA or 
MASTERCARD, call toll free 800-227- 
1617. ext 335 (800-772-3545, ext. 335 
in California). To order by mail, send 
your check to Strategic Simulations Inc. 
Dept. CC3. 465 Fairchild Drive, Suite 108. 
Mountain View. CA 94043. All our games 
carry a 14-day money back guarantee. 

Apple Is a registered trademark of Apple Computer Inc. 
© 1981 by Strategic Simulations Inc. All rights reserved. 



STRATEGIC SIMULATIONS INC 



PLAY BASEBALL 

It may sound WlfJlE.al.al. aTmll. 

ridiculous, but JK nnW "C^® W 

that's exactly what f^ML Wi I jmj « 
COMPUTER ^^ 

BASEBALL™ lets you do. With this highly realistic 
strategy game and your Apple® computer, you can 
manage any team you like — from the neighbor- 
hood hackers to the 1944 St. Louis Browns! 



ALL THE OPTIONS of a big time manager are at 
your disposal. For example, you can tell your 
hitters to steal or bunt, your outfield to play 
shallow; your infielders to come in at double-play 
depth or in all the way. You can even visit the 
mound to see how the pitcher's doing and per- 
haps dig into the bullpen for a reliever. 

For you historical buffs, the data for over 20 great 
past and present major league teams are provided 
so you can re-create immemorable games 
that were and those that might have been. ^. , 

THE COMPUTER RESOLVES the action 
based on your decisions and the reams of player 
statistics you've fed into it. such as a pitcher's ERA 
strikeouts, and won-Ioss record or a hitter's batting 
average, home runs, stolen bases.... 

CIRCLE 201 ON READER SERVICE CARD 




Using animated, color Hi-Res graphics, the 
computer presents an amazingly realistic simu- 
lation of baseball. It is so true to life that a hitter 
with a high RBI total will be biased to hit 
more often when runners are on base. On 
potential double plays, it will check for the 
fielding abilities of the players involved and 
for the running ability of the batter and person 
on first base. It even accounts for streak hitting 
and pitching. 

As if all this weren't enough, the computer 
will also manage the opposing team during solitaire 
play. 

How much does it cost to own all the 

baseball teams in the world? Just $39.95. 

COMPUTER BASEBALL comes with the 

game program disc (for a 48K Apple II with 

ROM card and a mini floppy disc drive), a 

rule book, and various player-aid charts. 

So you see. playing baseball with an 

Apple isn't outrageous at all. In fact, it may 

be more fun than the real thing. Give it a 

try today! 

To order with your VISA or MASTER- 
CARD, call toll free 800-227-1617. ext 335 
(800-772-3545. ext. 335 in California). To 
order by mail, send your check to Strategic Simulations Inc. 
Dept. CC3, 465 Fairchild Drive, Suite 108. Mountain View, CA 
94043. California residents, add 6Vi% sales tax. 

All our games carry a 14-day money back guarantee. 




Y 




The Second Creative Computing Chess Tournament 




Stephen Kimmel 



s 



"The time has come, " the Walrus said. 

"To talk of many things: 

Of shoes and ships and sealing wax 

Of cabbages and kings 

And why the sea is bailing hot 

And whether pigs have wings. " 

—Lewis Carroll 



If you've read Through the Looking 
Glass you know that Alice encounters a 
vast assortment of chess pieces. Most talk 
and many aren't quite what they appear 
to be. In many respects. Through the 
Looking Glass is Lewis Carroll doing to 
Chess what he did to playing cards in 
Alice's Adventures in Wonderland. The 
adventures are just as strange. In many 
ways it is like running this tournament. 

The editor of this sage publication was 
so impressed with the job I did last 
year— sometimes they are easy to 
impress— that she asked me to do it again. 
Mad fool that I am. I accepted. Here 
then, gentle readers, is the journal of my 
adventures in the looking glass house of 
computer chess. 

As you recall from our last episode. I 
had worked my way through five programs 
and dedicated computers armed to the 
teeth with salt and healthy skepticism. 
Two of the products. Microchess 1.5 and 
the JS&A Chess Computer, were found 
to be sadly wanting. I predicted that they 
would either be replaced by better products 
or would disappear. JS&A has dropped 



Stephen Kimmel. 4756 S. Irvimjton Plaee. Tulsa 
OK 741.15. 






out of the computer chess business. Occa- 
sionally you'll still find Microchess in a 
Radio Shack and in large software house 
ads. Normally they say that its principal 
asset is that it is easier to beat than Sargon. 
One product. Boris, was found to be 
adequate. Sargon and Chess Challenger 7 
were easily the best of the group. I 
predicted upgraded versions of those 
products. And we've gotten them. 

Cabbages 

Shortly after last year's tournament we 
got our first entrant for this year. It was a 
listing from Roger Brown's "Basic Software 
Library." Those are the large orange books 
that go for around $20 apiece. Being a 
registered idiot. I started typing it into my 
trusty TRS-80. Hours later, with sore lingers 
and strained eyeballs, I had it up and 
running. Several hours later I had it making 
nothing but legal moves and playing with 
a modicum of sense. 

Chess in Basic? Yep. Consider: essen- 
tially all chess programs are written in 
machine language for one fundamental 
reason— speed. To make a good chess 
move using current decision strategies 
requires examining hundreds of possible 
combinations. For a more extensive dis- 
cussion of how this is done I'll refer you 
to David Levy's column. "Intelligent 
Computer Games." Even in machine 
language, some of the programs seem 
awfully slow and arrive at imbecilic 
moves. 

How will a Basic program that plays 
chess act? If it tries to go through the 
entire search procedure as currently 
implemented, the computer will appear 

38 



to have locked up. It may take the program 
hours to arrive at pawn to king four. The 
other choice is to make a very shallow 
search that can be done in a reasonable 
amount of time. Of course if you can't see 
beyond the end of your nose you'll play 
terrible chess. 

Basic Chess plays the worst game of 
chess I have ever seen from a program, a 
rank beginner or a chimpanzee. I tried. I 
couldn't lose to it. It doesn't see deep 
enough to know if you are in checkmate. 
Figure 1 is from a game with my human 
player. You will note that Basic Chess 
has taken a pawn with its queen and has 
the human in check. You will also note 
that the queen is sitting directly next to 
the king and is undefended. Net result: 
Basic Chess has just swapped its queen 
for a pawn. The display is as marginal as 
is conceivable. 

As Thumper said in that immortal classic 
of pride and passion. "Bambi." "If you 
can't say something nice, don't say anything 
at all." 



BASIC CHESS 


BR 


BN 

& 


BB 


X 


BK 


BB 


BN 


\ / 
BR 


/ 
BP 

C s l 


BP 


\ / 
BP 




BP 


BP 


BP BP 








X\ 




X 




X 


A 




X 








, y 












WN 






X 


A 




/ \ 


w 




X 




WP 


WP 


WP 


BQ 




WP 


WP 


\ > 

WP 


WR 


\ / 
WB WQ 


WK 

• 


WB 


WN 


WR 


HUMAN 1000 



Figure I. Basic Chess captures the queen pawn 
and puts while in check... demonstrating just how 
had a chess program can he. 

The Basic Chess program has one nice 
feature. Since it is written in Basic, it is 
easy to figure out what is going on inside 
of it. And it is a snap to make it play 
better. That's not quite a good enough 
reason for me to fork out the $39.95 for 
the book. I have no use for the medical 
billing program, the word processor or 
the utility program that round out Volume 
VII of the series. Nor would 1 spend the 
$9.95 for the cassette tape available if 
you call 800-528-6050. But. if your money 
is burning a hole in your pocket that 
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Liiiii 



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REASONS TO MAKE 
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CIRCLE 244 ON READER SERVICE CARD 



Cabbages, continued... 

lose to Microchess. These were the only 
games Microchess won in this year's 
tournament. If these two programs were 
on a vaudeville stage they would be up to 
their ears in cabbages and tomatoes. 

Enter Creative Computing 

The second program to come in was Z- 
Chess which is offered by the Software 
Association (713-482-0883) and Creative 
Computing Software (800631-81 12). Say, 
that second group has a familiar sounding 
name. Now you might wonder if that will 
bias my report. I ask no quarter and I 
give none. I will take no prisoners. I will, 
however, tell you what is good about Z- 
Chess before I tell you what is wrong with 
it. 

Z -Chess fits the mold of the Creative 
Computing image of the human-computer 
relationship. In the early days of personal 
computing— forgive me this brief digres- 
sion, I promise that I will tie it all back 
together— computer programs and games 
were difficult to operate. The usual mold 
was for them to be abusive and offensive. 
It was a common occurence to push a 
wrong button and have your computer 
say: "Because of your complete incompe- 
tence, the Klingons have taken over the 
Federation, you stupid jerk!! 

It appears to me that the software people 
at Creative Computing believe that com- 
puter programs should be easy to operate, 
congenial and generally a pleasant exper- 
ience. Their software frequently has heaps 
and gobs of instructions and sometimes 
will even give examples of the play. The 
formats are designed to be easy to work. 
It seems that it is more important to 
Creative that the program be easy to work 
than to have it do the best possible job. 

Z -Chess is the easiest computer chess 
program to use. You don't have to learn 
strange nomenclature or consult page 14 
of the instruction book. There aren't any 
secret sequences of keys necessary to show 
the board. All of the squares are numbered 
and all you have to do is type the number 
of the square you want to move from and 
the number of the square you want to 
move to. It's that simple. The program is 
ruthlessly forgiving on input. 

It's too bad it doesn't play very good 
chess. 

The ads say, "Possibly the fastest good 
strategy chess game available." That state- 
ment requires closer examination. Note 
that it said "possibly." It isn't the fastest 
good strategy game available. The use of 
the word "strategy" rather than the word 
"tactical" normally means that it has the 
right theory in mind but that it may slip 
up on the little details. The advertisement 
is mostly smokescreeen and double 
speak. 

The graphics are somewhere between 
adequate and mediocre. The king and 
queen are differentiated by the letter on 

CREATIVE COMPUTING 



the top. The squares are backwards. The 
square in the lower lefthand corner is 
supposed to be white rather than black. 
(This has been corrected in the new version. 
Z-Chess III. which also incorporates an 
improved strategy.) 

Z-Chess stomped Microchess and Basic- 
Chess but that doesn't take too much. It 
lost games to Sargon and Human 1000. 

At this point I was afraid that the 
prospects of having a good tournament 
were pretty bleak. Perhaps there would 
be no drama this time, no waiting for the 
outcome of the final game to determine 
the winner. Perhaps there would be nothing 
but mediocre new entrants. Perhaps there 
would be no serious challege to last year's 
winner, Sargon. The next entrant gave 
me nothing to hope about. 




Chessmate-80 is a product of the Instant 
Software line. You can order one by calling 
603-924-72%. It is perhaps best considered 
by comparison to Z-Chess which is about 
its closest match in this tournament. 
Chessmate has a Basic language loader 
that displays commercials while you wait 
for the program to lewd. It's kind of a 
cute idea. I would have perferred instruc- 
tions, graphic display, practically anything. 
Still it does beat watching the little flashing 
stars. 

The instructions to Chessmate-80 are 
difficult at best. After three games. I lost 
the instruction sheet. I was unable to make 
the program do anything until two weeks 
later when the new set of instructions 
arrived. They were very good about that. 
Actually I was able to make the game 
show the square numbers by simply pressing 
the "I" key. That is a very nice feature. I 
could play a plain vanilla game of chess 
but I couldn't remember how to castle. 
Several games later I am still helpess 
without the instruction sheet. You see. 
the program has so many features and 
functions that it takes a rather complex 
instruction entry procedure. 'VA(Enter)" 
makes the program display all the moves 
that it considers. I consider all this unnec- 
essarily complex. 

AUGUST 1981 



e graphics are nice enough consid- 
ering that it is on a TRS-80. At least they 
have the color of the squares right. 

Unfortunately. Chessmate-80 doesn't 
play very good chess either. It beat— ho 
hum — Basic Chess and Microchess impress- 
ively. And it lost both games to Z-Chess. 
The advertisements talk about how you 
might be embarassed to play Chessmate- 
80 in public. Well, if you are very easily 
embarassed or you're a bad chess player, 
or you might be embarassed to be seen in 
public with Chessmate-80. At $9.95 (plus 
$1 for shipping and handling) Chessmate- 
80 is the cheapest chess program around 
that is worth playing. That seems to be its 
principal redeeming virtue. I consider 
Chessmate-80 and Z-Chess to be about 
on a par with our old friend Boris with /.- 
Chess being slightly better and Chessmate- 
80 being slightly worse. 

And Kings 

Which brings us to our old friend Boris. 
Where is Boris? What happend to Chafitz 
and the computer chess game they claimed 
would always be king? Well, it seems that 
Chafitz is out of the chess business. 
According to their press release. "Chafitz. 
Inc. has announced that its Special Products 
Division will no long be distributing chess 
products. Chafitz has taken this action in 
order to concentrate more of its resources 
on expanding its well established Retail 
Division, which is a leader in the Wash- 
ington area consumer electronics market. 
Their recent entry into personal computer 
sales has been extremely successful and 
they are implementing some innovative 
marketing plans in the video market." 
The Chafitz press release goes on to say 
that they have completed licensing agree- 
ments for the "revolutionary" Auto 
Response Board with AVE microsystems 
and that Chafitz is negotiating the rights 
for the other products. 

A quick call to AVE Microsystems got 
Dale Folwell. president of the company. 
According to Mr. Folwell. AVE has always 
been the manufacturer of the Auto 
Response Board. They plan to work 
through the same sort of distribution system 
that the Boris unit has always gone through. 
He offered to send us one of their $475 
models for use in the tournament. Drtx>ling. 
1 accepted. 

It seemed obvious to me about this time 
that Sargon was going to be the champion 
again. It had handily dispatched the new 
entrants. If the Auto Response Board was 
simply a recycled Boris program in a fancy 
new wrapper, then it would mount no 
serious threat to Sargon 's supremacy. Yet 
another new program came in about this 
time and ended any serious possibility of 
a repeat winner. When Sargon fell from 
serious consideration, it fell without a 
whimper. Sargon was lifted up. carefully 
peeled, dissected, and thrown away like 
the used wrapper from your local death- 
burger joint. The new program was clearly 

43 



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CIRCLE 155 ON READER SERVICE CARD 



Cabbages, continued. 



a superior chess player and it further 
demonstrated it by beating Z-Chess and 
Chessmate-80. and (Do I have to keep 
saying it?) Basic Chess and Microchess 
were laughed out of the tournament. We 
watched silently as the newcomer devas- 
tated everything in sight. 

Sargon II had arrived to lay claim to 
the crown. The advertisements state it 
simply enough: the best has gotten better! 
The program has a new set of graphics 
about which I have mixed feelings. It has 
faster levels of play and a new level for 
those of you easily intimidated by Sargon s 
play at its better levels. Don't feel bad. 
Sargon at level 3 is better than the majority 
of human players. And there are three 
levels above that. The program even has 
a hint feature that tells you what it thinks 
your best move is— I think. It is possible 
that Sargon is giving you slightly inferior 
moves, but that would seem extremely 
petty of such a fine program. All in all 
this is a fine program although the price. 
$29.95. is steep. 

Of course, this might well be the end of 
the story. A worthy champion had been 
found. But that would be both dishonest 
and rather dull. As it turned out there 
were serious challengers to threaten Sargon 
H"s claim on the crown. I wasn't ready to 
hand first place to Sargon II. 

The Challengers 

The package that brought the Auto 
Response Board from AVE Microsystems 
was huge. It could easily have been used 
for the top of a nice card table. Drooling 
on the wife's new carpet. I tore away the 
box to reveal the new dedicated chess 
computer. I gasped. It was magnificent. 
It was beautiful. It was obviously what 
God intended a dedicated chess computer 
to look like. It was a two foot square of 
inlaid hardwoods with tiny red lights in 
the corners of the squares and unobtrusive 
buttons down one side. A second package 
contained the largest transformer I've ever 
seen and the best set of chess pieces I've 
seen in ages. It was what you would expect 
if you'd paid $475 for an electronic game. 

Then I noticed the name. It said Chafitz 
all right. It also said. "Auto Response 
Board Sargon 2.5 Computer Chess Pro- 
gram." Sargon 2.5? I had heard that Chafitz 
had hired the now famous Spraklens to 
work on their Boris program. What appar- 
ently has happened is that Boris has been 
dumped completely, remaining perhaps 
in the little Boris Diplomat units, in favor 
of an updated version of the Sargon 
program. Or is it? The name implies that 
this is a later product. Is it just some new 
form of advertising hype? Are they just 
using the name to imply something that 
isn't true? Perhaps the only modification 
is the change in the input and output 
routines. It demanded an immediate match 
with Sargon II to set the issue straight. 



But alas, gentle reader, the issue isn't 
that simple. There is yet another serious 
challenger for the crown. This one was 
expected, although I must confess that its 
strength surprised me. Atari has been 
making fine video games for a number of 
years and is a recent entrant into the 
personal computer field. I happened to 
have a Video Computer System to provide 
the color graphics and sound for the games 
I need to keep my kid from throwing 
away my life savings on the Atari games 
in the arcades. My kid is three. 

For this tournament we used the car- 
tridge program for my video unit. The 
play is with the joysticks, which is quite a 
switch from the strange nomenclature of 
most of the programs. You simply direct 
an X to the piece you want to move. 
When you get there you press the red 
button to "pick up the piece." Move the 
X again until you find the right place and 
press the red button again. The move is 
made and the computer begins to think 
by throwing the screen into a wild series 



Perhaps there would be 

no serious challenge 

to last year's winner, 

Sargon. 



of color contortions. The screen reappears 
with Atari's move. The X shows where 
the piece came from and the moved piece 
flashes so that you can tell immediately 
where it went. What could possibly be 
simpler? 

The graphics are really strange on the 
Atari. The board has a huge amount of 
blank space all around. They haven't made 
much of an effort to make the board as 
large as possible. With a relatively small 
TV set like mine this can get to be a 
strain. The computer makes a particularly 
offensive sound when it has you in check. 
I suppose it goes without saying that when 
you have a few controls available that 
setting up a special position is a pain in 
the neck. 

But the Atari program does know how 
to play chess. It has an opening book like 
the best programs. Its play seems to be 
free of gross errors and there are no obvious 
stylistic errors. 

One last serious challenger made it in 
time to be included in our tournament. 
Another brief digression: the world chess 
tournament for computers has been the 
habitual domain of the monster computers. 
The championship seems to be perman- 
ently resident with Chess 4.9 or Belle or 
Duchess. All of the programs run on the 
giant computers. There are two smaller 
programs that have made serious inroads 



into this territory and have begun laying 
waste to the theory that a good chess 
player has to be as big and as fast as a 
Cray-1. One is the Sargon 2.5 Auto 
Response Board, which finished seventh 
in last year's tournament. It came close to 
winning its game with Belle, the second 
place program, but blew a won game. 
That loss was in part responsible for the 
other program on a reasonable size machine 
finishing sixth in the tournament. 

David Kittenger's Mychess is a terrific 
program that runs on the Cromemco Z2D 
and Z.M ) machines. Both are substantially 
larger than my TRS-80, but they will fit in 
a regular office and still have room for 
something else. And you get them for 
under $20,000. Because of its high finish 
and the difficulty in finding a $10,000 
computer to borrow 1 decided to hold 
Mychess out and have the champion play 
it in a special pair of games. 

If you have a Cromemco machine that 
takes 8" floppy disks and if you have any 
interest in chess then you absolutely have 
to buy Mychess. Forget the Dazzle chess 
the Cromemco dealers push. It is bad. 
And it requires that you have a color TV. 
Mychess requires only the machine. By 
now Kittenger may even have it on 5" 
floppies. You can order by writing to 
Computer Services, 2431 Lyvona Lane, 
Anchorage. AL 99502. 

I suppose this is the appropriate time 
to say something about the Chess Chal- 
lenger line. There are at least two new 
products in this fine group. The Voice 
Challenger and the Sensory Challenger. 
Except for the display at my local Sears I 
haven't seen either one. I am told by 
owners that the changes are superficial. 
Voice Challenger, as you would expect, 
talks to you confirming your move and its 
move. Sensory Challenger. I understand, 
senses the movements of the pieces. I'm 
afraid to say more since that's all I know. 
Fidelity did not send in a machine for us 
to use. Since I was on my own finances. I 
went for cheap and got the old Chess 
Challenger 7. which you can get now for 
under $100. 

Tweedledum and Tweedledee 

The required matches between Sargon 
2.5 Auto Response and Sargon II began 
with Sargon 2.5 playing white. Sixty-four 
moves later, the longest match of the 
tournament, Sargon 2.5 emerged the 
winner. Obviously the improvements aren't 
too great. The advanced Sargons play a 
very similar game, surely the mark of 
Dan and Kathe Spraklen. After achieving 
the material advantage of a piece or a 
couple of pawns, they begin to remove 
pieces from the board with almost reckless 
abandon. It is almost always an even swap. 
Frequently the swap is made in such a 
way as to inflict structural damage as 
well. In my judgment, this is very sound 



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As usual, Micro Lab has provided 
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and statements are included in the 
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and statements in the first afternoon. 

The Invoice Factory will change. As 
we develop new ideas we will add 
them. As always we will read your 
suggestions and listen to your needs. 
From time to time a new version will 
be issued. Each package includes an 
original set of two disks along with 
two back-ups. If you blow a disk there 
is no delay in operations. You are 
never without a working program. 
Micro Lab's Extended Warranty for 
The Invoice Factory is $50 annual- 
ly. This will allow the policy holder 
free renewals on the program disk- 
ettes (on like media) in case of 
any damaged program disks, as well 
as updates when new features are 
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now included in the purchased price. 

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voice Factory. The Invoice Factory is 
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written by Bill Passauer. You may see 
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AUGUST 1981 



45 



CIRCLE 156 ON READER SERVICE CARD 



Cabbages, continued. 



S ARGON 2.5 




ATARI 

Figure 2. 

20... RxP!ck 

21 PxR BxQ ck 

Eliminates all doubt about the outcome. Why not 

21 QxR? Because the queen cannot mote without 

nutting while in check. 



1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

24 

25 

26 

27 



Atari (white) 

P-Q4 

N-KB3 

N-QB3 

P-K3 

B-Q3 

OxB 

PxP 

OK2 

O-O 

R-Ql 

B-K4 

P-QR4 

P-KN3 

B-Q3 

B-Q2 

B-B4 

N-Nl 

BxP 

PxN 

OB2 

PxR 

KxB 

K-Kl 

N-B3 

K-Bl 

K-Nl 

K-RI 









ATARI 












BR 


BR 




X 




X 










X 


BK 


BP 
















BP 




BP 








WR 


BP 












WN 










X 


WP 


WP 












WP 


X 








WP 


WP 


WP 


X 








X 




< 7 

WK 



SARGON 2.5 



Figure "I. 
RxRP RxP 

R-R7ck KB.1 
R-Rn ck KB2 

Uails to a potential stalemate hy repetition. Sargon 
2.5 chooses to throw away the game instead. 



Sargon 2.5 (white) 

1 P-K4 

2 N-KB3 

3 B-N5 

4 P-Q4 

5 NxP 

6 N-QB3 

7 B-N5 

8 BxN(B3) 

9 BxN 

10 NxP(B3) 

11 RxQ 

12 N-N5 

13 NxB ck 

14 RxP 

15 O-O 

16 R-Kl 

17 RxB??? 

18 RxP 

19 N-Q4 

20 R-K6 

21 R-K5 

22 P-QB3 

23 P-QN3 

24 RxRP 

25 R-R7 ck 

26 R-R6 ck 

27 R-R7 ck 

28 N-K2 



Sargon 2.5 (black) 

N-KB3 

N-QB3 

P-04 

B-N5 

BxN 

P-K4 

NxP 

B-B4 

O-O 

0-03 

P-B3 

KN-N5 

0-K3 

QR-K1 

P-Q5 

Q-Bl 

PxP 

NxB 

RxP 

RxPck 

BxQck 

0-B4 ck 

OxP 

R-Klck 

N-K5 

0-B7ck 

NxP checkmate 



Atari (black) 

P-K4 

N-QB3 

N-K2 

PxP 

P-04 

B-K3 

PxP 

PxB 

BxB 

0x0 

B-KB4 

B-Q3 

PxN 

R-0B1 

P-OR4 

B-N3 

RPxR 

K-Bl 

P-B4 

K-B2 

KR-01 

R-ON1 

0R-0B1 

RxP 

K-B3 

K-B2 

K-B3 

R-Q8 checkmate 



Sargon 2.5 chooses to throw away the 
game rather than settle for a stalemate 
and in doing so throws away the 
tournament. 






46 



chess— if somewhat dull. A three pawn 
advantage may not seem like much when 
the board is full of pieces but when there 
is only one piece and three pawns against 
one piece and six pawns the eventual 
outcome is no longer in doubt. Both Sargon 
2.5 and Sargon II do this. 

Sargon 2.5 has one other feature that 
none of the others has. Most of the 
programs sit there and scan the keyboard 
waiting for you to make your move. Not 
Sargon 2.5. When you think about what it 
should be doing, it becomes obvious. The 
computer is sitting there thinking about 
the keyboard. Why not have it think about 
the game and check the keyboard every 
few milliseconds? The only question is 
what it will think about. Both of the Sargons 
give hints about your best move. Sargon 
2.5 assumes that you will make the best 
move and then thinks about what it will 
do when its turn comes again. See? I told 
you. Obvious. 

During the course of a tournament there 
is always a need to leave the machines for 
a brief time. I always felt like I was cheating 
when 1 left Sargon 2.5. Its opponent would 
make its move and wait while Sargon 2.5 
would be doing progressively deeper and 
deeper searches. 

Then why doesn't Sargon 2.5 play better 
chess than it does? the program has a 
fatal flaw: it will not settle for a draw! Be 
it behind or be it ahead, if it looks as 
though it is going to settle into a stalemate 
by repetition. Sargon 2.5 will pick an 
inferior move. It cost Sargon 2.5 the second 
game with Sargon II. In 63 moves. Sargon 
II had drawn even with its supposedly 
vastly superior brother. 

Enter Atari Video Chess. When Atari 
played Sargon 2.5 as white, the game was 
over in a mere 27 moves. The match was 
no longer in doubt after move 20 shown 
in the diagram. Of course, we wrote this 
off as insignificant. Sargon 2.5 had simply 
destroyed another inferior program. Or 
so we thought. The second game also 
lasted 27 moves. It also demonstrates the 
classic flaw of Sargon 2.5. Despite what 
might be described as a terrible move at 
move 17. Sargon 2.5 is still even materially 
and Atari's pawn structure is in shambles. 
With Atari's move giving it the possibility 
of a quick mate (any rook to the last file) 
Sargon 2.5 begins the fatal series of moves. 
They dance a quick polka of checks and 
Atari king moves. Seeing that they are on 
the verge of a stalemate Sargon 2.5 choses 
the final knight move. Why not move a 
pawn and make checkmate impossible? 
Why not the bad king to bishop one or 
the terrible knight to bishop three? Who 
knows what evil lurks in its electronic 
heart? Instead. Sargon 2.5 picked the worst 
possible move and threw the game away. 
Atari, being no fool, moved the appropriate 
rook and ended the claim of Sargon 2.5 
to clear superiority 

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AUGUST 1981 



47 



CIRCLE 248 ON READER SERVICE CARD 



Cabbages, continued. 

Could it be that the unheralded Atari 
was actually the best chess playing product 
available this year? Stay tuned and find 
out. 

The second half of the tweedledum 
tweedledee team of Sargons then took its 
shot at the upstart Atari. The diagram of 
this game shows a typical position for the 
current Sargons. The pawn advantage of 
Sargon II should be enough to assure the 
eventual outcome of the game. Sargon II 
has overlooked one small detail, however. 
Atari has a forced mate in two. I'll leave 
it to you to pick out the required moves. 
Positions like this clearly demonstrate how 
deeply a program can examine a position. 
Fortunately for Sargon II, Atari has also 
overlooked the forced mate in two. About 
a million moves later, Sargon II cashes in 
its pawn advantage and makes a quick(?) 
end of it. The second game ended more 
quickly. Thirty moves into the game. 
Sargon II had a one pawn advantage but 
Atari had a better pawn structure. Neither 
one could decide what to do. They spent 
the next ten turns making the same moves 
over and over again. It ended in a stalemate 
by repetition. 



And The Winner Is... 

And now for something completely 
different. If you read the report of last 



SARGON II 




ATARI 




Figure 4. Atari has a forced male in two moves, 
but lacks the depth to see it.. .and so moves RxP 
instead. 

year's tournament (soon to be a major 
motion picture) you will have noticed the 
lack of human players. This is simply a 
matter of self-defense. Last year we had 
five electronic players and two humans. 
We played 42 games. It came close to 
breaking up my marriage. This year we 
have ten electronic players. That's 90 games 
and my wife is in Wisconsin on a prolonged 



visit with her grandmother. Add two 
humans and you have an additional 42 
games. That's as many as last year's total! 
Should I put in three times as much work 
this year? Sorry, boys and girls. No way. 
The winner of last year's tournament 
was Human 1400, not Sargon as some 
would have you believe. This year he 
only played my leading contenders: Sargon 
II (14-1-1), Sargon 2.5 (14-2-0), and Atari 
(13-2-1). The outcome of these matches 
would determine the winner and which 
program would go on to challenge Mychess. 
Human 1400 learned his lesson about 
electronic chess players in last year's 
tournament. They are relentless and they 
never make mistakes of simple oversight. 
Human 1400 takes none of the programs 
lightly and doesn't start laughing until he 
is well ahead. Human 1400 brushed aside 
Atari in two quick games and it was clear 
that he was playing at close to his potential. 
It was also clear that Atari wasn't all that 
good. It is probably about as good as the 
old Boris units. 

Sargon II fared a little better in its first 
game and managed to defeat Human 1400 
as black. As white, Sargon II collapsed 
into defeat and ritual suicide. This put 
the pressure squarely on Sargon 2.5. It 
could still win the tournament with a victory 
and a draw against Human 1400. Two 
victories would make it clear cut. To be 



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fair, none of these programs is 
designed to play other computers. They 
are designed to play humans. Human 1400 
was on the ropes against Sargon 2.5. Despite 
playing a basically solid game he was losing 
to the electronic thoroughness of the 
machine. Perhaps in desperation. Human 
1400 moved his king from bishop two 
back to bishop one. Those of us who had 
watched Sargon 2.5 work its way over the 
others held our breath. Sargon 2.5 repeated 
its move. Human 1400. who was breathing 
noticeably easier, continued the invitation 
to stalemate by moving back to bishop 
two. He hoped that he would sneak out 
with an undeserved stalemate. We waited 
to see if Sargon 2.5 would make some 
drastically horrible move. Finally the 
machine moved. It wasn't a horrible move. 
It was merely inferior. Sargon's great flaw 
had risen once again like something out 
of a Greek play. Human 1400 sat without 
moving for a full minute before seizing 
the opportunity and eventually cashing in 
for the victory. The flaw had cost Sargon 
2.5 a game against Atari, it had done it 
again with Human 1400 and it lost the 
tournament. 

In what should probably be considered 
a major upset Sargon II had defeated 
Sargon 2.5 for the right to meet Mychess. 
In the final analysis the tournament pivoted 
around the fact that Sargon II was willing 



MYCHESS 


BR 


X 




X 


BR 


X 


BK 


X 


X 


BP 


X 




X 




X 


BP 




BP 




BP 




BB 


BP 










WP 




BP 










WR 










X 


X 


v. / 
WN 








WN 




WP 


WP WP 






WP WP WP 


X 






X 




WK 

• s 


SARGON II 



Figure 5. Mychess to move. 22... BxS(F6xL"ti ami 
Mvchess announces mate in eight. 



lo settle for a stalemate with Atari. If it 
weren't for the flaw Sargon 2.5 might 
be— would be— the better program. But 
that qualifies as Monday morning quarter- 
backing. 

Sargon II played two games against 
Mychess. The first one seemed to go on 
forever, lasting 61 moves. Both programs 
did an exceptional job of predicting the 



moves of the other. Mychess. like Sargon 
2.5, thinks on the opponent's time. Thus, 
it can see the position deeper and even- 
tually won the game. The diagram shows 
a position from the second game. Mychess 
priK'laims the best series of moves, a full 
eight moves ahead! This is an incredible 
feat for a small computer program. Sargon 
may be capable of it but somehow I doubt 
it. The next eight moves click off neatly 
with only one variation from Mychess's 
proposed continuation. At move 29 
Mychess completes the kill and defeats 
Sargon II for the second time. 

The Dust Settles 

Did we actually see a match of programs 
or was the outcome foreordained by the 
fact Sargon II was playing on a TRS-80 
with its 1.77 mhz dock instead of the 
Cromemco Z-80 with its 4.00 mhz clock? 
I tend to think so, but I would like to see 
the two play on a more equal footing. 
The Spraklens' tournament version of 
Sargon has defeated Mychess before. 
Nevertheless. Mychess is the finest chess 
playing program commercially available. 
I just hope that Kittenger puts in the 
effort and translates the program to run 
on something a little more common than 
the Cromemco Z2D. 

Sargon II is the best program available 
for the Apple and the TRS-80. Sargon 2.5 



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CIRCLE 1170N READER SERVICE CARD 



Cabbages, continued... 

is the best dedicated player currently 
available although I haven't had the 
opportunity to see Radio Shack's new 
machine. Chess Challenger 7 is still a fine 
machine and fur the money is probably a 
better buy than Sargon 2.5. If you own 
one of the Ataris and are interested in 
chess, then by all means buy a Video 
Chess program for it. Assuming, of course, 
that you aren't like me going "gasp, choke, 
cough, cough, cough" when you see a $45 
price tag. 

The chart indicates the final outcome 
and my guess as to the rating of the various 
programs. 

The Future 

What will the future hold for computer 
chess? There are three developments that 
I find extremely interesting. Both JS&A 
and Chafitz have gotten out of the dedi- 
cated chess computer business. Fidelity 
seems to be keeping a lower profile. It 
could very well be that the market for 
dedicated chess computers is approaching 
saturation. The novelty has worn a little 
thin and there simply aren't that many 
people willing to plunk down $100-$500 
for a machine that doesn't do anything 
but play chess. 

If there was much of a future in the 
market I would expect Texas Instrument? 
to be in there. They have a program. 
They have the expertise to make a com- 
petitive product. You would tend to 
conclude that there is no market. On the 
other hand Tandy is introducing a dedi- 
cated chess player. Tandy has made some 
mistakes in their day and I think this is 
another one. I expect that by Christmas 
of 1982 the Tandy chess machines will be 
gone. 

On the other hand, chess programs are 
now as common as personal computers. 



Although Microchess has functionally 
disappeared from the market there are 
several others to take its place. It almost 
seems to be a requirement that a home 
computer have a chess program. I would 
be interested to see what percentage of 
people own one. Each of the current 
programs seems to be carving out its own 
comfortable niche. The Sargons are avail- 
able for the good player. Z-Chess is the 
program for the novices. Video Chess is 
for the Atari. Mychess is for the Cromemco 
scries. 

Will there be other programs? Possibly 
not. The major software lines all have 
programs. There is very little prospect 
for success with a new program. 

Still there are 400.000 programmers out 
there working on personal computers and 
I'm sure some of them are working on 
chess programs. You will probably start 
seeing advertisements selling chess pro- 
grams you've never heard of, and all you 
have to do is send your $14.00. cash or 
check, to apartment 322. After a few 
months the ads will disappear. The pro- 
grammer trying to sell his own program 
will have run out of money. On the other 
hand, if your program can beat Sargon. 
there is hope for you. It may take a while 
but there is hope. Kittenger. for example, 
may decide to translate Mychess for the 
TRS-80. 

One thing we can say with certainty is 
that computer chess is out of the dark 
ages. Now the winners can really be called 
kings. We will have to save our cabbages 
to throw at some other stage. 

Special thanks go to Dick Havens of 
Computers International of Tulsa for the 
loan of the Cromemco Z2D, to Rick 
Helmrich for the loan of a TRS-80 and to 
Gary Krasner who played several of the 
games. 







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W 
B 












: : 


* 
* 


* 
* 


* 
• 


6-10-0 


1000 


Chessmate 


JO 


W 

B 














" 


* 
* 


* 
* 


4-12-0 


800 


Microchess 


2 


W 
B 


















* 
* 


2-14-0 


500 


Basic Chess 


W 


















: : 


0-16-0 


200? 






B 


















: : 







Fixurc 6. The results of the individual matches. 



S w 






50 



itii>)>e lOBfiS 



I'm a firm believer in the fact that 
Murphy was a prophet of God. I finished 
putting in a couple of hundred hours on 
"Of Cabbages and Kings" (about which 
time I couldn't have cared less if I never 
saw another computer chess game again 
in my life) and along comes a group of 
new products to make me look bad. 
Gambiet 80 claims to be "The World's #1 
Microcomputer Chess Program." A TRS- 
80 version of Mychess appears claiming 
to be "King of the Hill" and to thrash 
routinely the various Sargons. None of 
which keeps Sargon from claiming to be 
the "state of the art." Indeed. Sargon seems 
to be the whipping boy in just about 
everybody's ads. If you can't do anything 
else, you can always claim to beat 
Sargon. 

All of these conflicting claims started 
my adrenaline flowing. They can't all be 
right! Somebody is not telling the entire 
truth! Despite all my good intentions to 
give up computing and become an axe 
murderer. 1 was irresistibly drawn to borrow 
a computer and sit down again locked 
hypnotically to the CRT. 1 am a creature 
driven by primal forces to expose false 
claims. I am a barely credible hulk ram- 
paging through microcomputer chess 
programs. 

The version of Mychess I had earlier 
was designed for the Cromemco with its 4 
MHz clock. That's twice as fast as the 
TRS-80 I had Sargon II running on. But 
the question remained; how much of 
Mychess's crushing victory was due to 
the clock and how much was due to 
superior chess playing ability? Since both 
computers are Z80 based, the difference 
should be significant. 

Mychess. from Programma International 
($34.95. 2908 North Naomi St.. Burbank, 
CA 91504, 213-954-0240) is. in fact, the 
same program. All David Kittenger and 
company did was to change the addresses 
from the Cromemco's free low memory 
to the TRS-80's free high memory. They 
have added a save game feature to allow 
you to save up to six games in progress. 
The program will run on a 32K TRS-80 
with one disk drive. 

Since Mychess is so large— at 30K the 
largest program I've seen on a TRS-80— it 
has to have its own DOS. They have taken 
this opportunity to introduce Securdos 
which very effectively prevents unauthor- 
ized copying. I ruined my one legal copy 
and none of the programs I had would 
even begin to copy it. So I proceeded 
with extreme caution. 

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CIRCLE 189 ON READER SERVICE CARD 



More Kings, continued. 

As you might expect, Mychess suffered 
from the slower clock. It was. however, 
still up to beating Sargon II. The first 
game gave every indication of going on 
forever. After four hours and sixty moves. 
Mychess had a commanding lead, but 
seemed to be having some trouble making 
the final kill. I awarded the game to 
Mychess and reversed the boards. The 
second game, however, had a slightly 
different outcome. Four hours later. Sargon 
II was a full rook ahead and was merrily 
picking off Mychess' remaining pieces. 
This game seemed beyond doubt so at 
2:30 a.m. I declared it a win for Sargon II 
and went to bed. I was the first time in my 
experience that a Sargon program had 
beaten Mychess. 

Mychess claims in the documentation 
that it has won 20 of 24 points with Sargon 
2.5 or about five out of every six matches. 
The Sargon 2.5 I used refuses draws— a 
major flaw. Sargon II doesn't have thai 
flaw and should be able to beat Mychess... 
perhaps. ..once out of every four matches. 
I've played the programs against each 
other four times now and the one in four 
ratio seems fairly sound. 

Mychess is not a polished commercial 
package. It desperately needs something 
to indicate that it isn't hung up. My printer 
caused that to happen several times and 
there isn't a clue except that an excep- 
tionally long amount of time has passed 
between moves and the fact that the 
keyboard won't respond. The graphics 
are non-existent and would look the same 
if done on a teletype. The Securdos is 
troublesome and occasionally fails to read 
correctly. In fact the only thing Mychess 
has going for it is the fact that it plays 
exceptionally good chess— for a small 
computer. 

With the relationship between Sargon 
II and Mychess firmly established. I moved 
on to Gambiet SO. By the luck of the 
draw it got to play Mychess first. 

Gambiet '80 is a European program by 
Win Rens handled by the Microtrend 
organization. It sells for $39.95 (the most 
expensive chess program I've seen) from 
Microtrend. USA 1900 Plantside Dr.. 
Louisville. KY 40299 (800-626-6268). Its 
early advertisements claimed it was the 
world's best. Later ads merely state that it 
is "A Microcomputer Chess Program in a 
Class of Its Own." Difficult to really attack 
that. Microchess is in a class of its own. 
too. 

To a large extent. Gambiet '80 is like 
all the others. It has reasonable, if slightly 
small graphics. The display always shows 
the last twelve moves and the numbers on 
the squares. If you have an expansion 
interface it will display the time for each 
player. Gambiet also gives you the option 
of printing the moves. All of which is very 
nice, but if you are going to be the world's 
best you have to do it with playing ability. 







In the first game Gambiet was so busy 
chewing up Mychess that it hardly paused 
to belch. It attacks ruthlessly and has no 
compunction about clearing the board of 
pieces. Mychess' predictions were consis- 
tently wrong, calling for major pieces when 
Gambiet moved pawns and pawns when 
Gambiet moved major pieces. That tended 
to make Gambiet look brilliant and 
Mychess look like an idiot. I haven't seen 
a game so fast since Boris dismantled 
Microchess. 

I was satisfied that the Gambiet ads 
were right. My task seemed straightforward. 
After beating Mychess. Sargon should go 
the way of all programs and Gambiet 
would be the new champion. One minor 
technicality: Mychess refused to cooperate, 
vowing to fight to the end. Mychess picked 
the rather off-beat English opening, pawn 
to queen bishop four. Gambiet was beaten 
on the opening move. Gambiet has no 
opening book preferring to calculate for 
basic principles. It seems to work fine on 
king pawn openings and isn't too bad on 
queen pawn openings. Gambiet is, however, 
quickly cut apart by irregular openings 
and is a sucker for gambits. 

So now it fell to Gambiet to recover its 
besmirched dignity, beat Sargon II and 
demonstrate its claim to world domination. 
Another small difficulty reared its ugly 
head to spoil the scenario. Sargon II didn't 
win those tournaments by rolling over 
and playing dead. It is a salty competitor 
that is almost never humiliated. What's 
more Sargon II and Mychess were in the 
corner trading notes when I broke them 
up to continue the tournament. Sargon II 
offered a gambit and Gambiet fell apart 
playing into Sargon's capable hands. 
Combined with an advantage in the opening 
and their combined willingness to swap 
pieces, they quickly stripped the board to 
Sargon's advantage. Finally Gambiet was 
forced to trade a rook for a promoted 
pawn and it was all over. 

Sargon II won in what might be consid- 
ered an upset. Only one game remained 
and suddenly a nightmarish possibility came 



52 



to mind. If Gambiet beat Sargon II. then 
everybody would have beaten everybody 
else and nothing would have been proven. 
The alternative was that Sargon II would 
win making it the clear winner despite 
the technical superiority of Mychess. 

The game began, and in Gambiet's usual 
style it was an early bloodbath. I was 
amazed at how quickly the major pieces 
were gone and each side was left with a 
queen and a half dozen pawns. Sargon II 
had the superior pawn structure having 
no doubled pawns and only one isolated 
pawn, but Gambiet's queen was still a 
very potent force. For fifteen moves— a 
full hour and a half— I watched them 
waltz back and forth with only the queens 
moving. Although not a stalemate by 
repetition technically, it certainly qualified 
under the spirit of the rule. I have no 
doubt I could have watched them for the 
rest of my life and they would still be 
dancing. 

A stalemate. Sargon II finished the mini 
tournament with a record of 2-1-1, Mychess 
2-2-0 and Gambiet '80 1-2-1. Sargon II 
was the winner, but it left a funny taste in 
my mouth. The results were so ambiguous. 
1 couldn't play the whole thing all over 
again. My eyes were failing and my wife 
was packing her suitcase. Ah. but life is 
never that simple. Enter yet another chess 
program with impressive credentials. 

Sfinks ($29.95 from William Fink, 1300 
SE 3rd Ave.. Deerfield Beach, FL 33441 ) 
is unique in this field in that it is the only 
program that plays something besides 
straight chess. It has four separate options, 
chess, problem setting, pre-chess and 
transcendental chess. Pre-chess? In pre- 
chess. you and your opponent take turns 
placing the major pieces on the first row. 
After they are all set you play the game 
by the usual rules. In transcendental chess 
the major pieces are placed randomly 
behind the pawns and the game proceeds 
as usual. This makes for a very refreshing 
game for those who are tired of plain 
computer chess. 

Sfinks has superior graphics and if 
hooked to an amplifier will beep when it 
makes its move. Like Mychess it comes 
with its own DOS. which makes it imper- 
vious to copying. It has nine levels of play 
ranging from one second response to two 
days at level seven. Its tournament level 
is level eight. This all seemed very similar 
to Chess Challenger 7 and. in fact. Mr. 
Finks worked for Fidelity during the 
developmment of the Challenger series. 
Sfinks incorporates many of the same ideas, 
but is definitely a different beast. 

Sfinks beat Gambiet '80 twice, though 
not without some bloodshed, and split a 
pair of games with Sargon II. Now came 
the cruncher — the two games with 
Mychess, but first a word from our 
arrrggghh department. Remember that 
both Mychess and Sfinks come with special 

CREATIVE COMPUTING 



DOSes. Since I am borrowing a computer 
to play these matches (surely you didn't 
think I was using just one computer!) I 
have to use what I can get. For this 
tournament I used a TRS-80 Model I and 
a TRS-80 Model III. Try as I might. I 
couldn't get the Model III to accept either 
Mychess or Sfinks. I was unable to play 
the two games against each other. 

Still unsatisfied with my three way tie. I 
tried once more for resolution. This time, 
instead of three minutes per move, every- 
body plays at his fastest setting — five 
seconds or less. My chair was swiveling 
back and forth so rapidly that I could 
hardly keep up with the games. The 
machines were making moves before their 
opponents had finished displaying their 
moves. 

And the results. Mychess and Sfinks 
beat Gambiet twice which confirms that 
part of the results. Sargon II, however, 
beat everybody else. Thus Sargon II, by 
virtue of a tie coming out of the main 
tournament and a clear victory in the 
speed tournament, is the winner. 

Mychess probably plays the best chess 
and if that's all you are interested in then 
that's the one you should buy. When 
Programma finishes the changes to include 
graphics and make Mychess a slick com- 
mercial product, it will be the best program 
around.. .assuming somebody better doesn't 



show up. I am a tightwad at heart and I 
can't see much to recommend Gambiet 
'80. It plays acceptable chess and has a 
few nice features, but it just isn't worth 
the money. 

That leaves Sargon II and Sfinks. Sargon 
II's chess playing ability is comparable to 
any of them, it is a thoroughly debugged 
commercial program and is cheaper than 
Mychess or Gambiet. Sfinks plays good 
chess and has the non-traditional chess 
options. Both cost just $29.95. Both have 



It could very well be 

that the market for 

dedicated chess 

computers is 

approaching saturation. 



good documentation. Both have good 
graphics. Sargon II is from a large company 
with the resources to support it and you if 
there are problems. Sfinks has a single 
fellow behind it so there may be less depth, 
but more personal help. Sargon II won 
the blitz tournament and has a score of 
very small factors in its favor. The margin 



over Sfinks is very slim. Sargon II is the 
computer chess program of choice and 
will be the one to which the others compare 
themselves for some time. 

Something important should be noted 
here. When I started this project, back at 
the dawn of time. Sargon and Chess 
Challenger were the winners because they 
played adequate chess and most of their 
competitors were just plain bad. The gulf 
was awesome. Last year it was the advanced 
Sargons and Mychess. The bad programs 
were few and far between with only the 
abysmal Microchess still on the scene. 
The overall quality has improved drama- 
tically. All of the programs in this batch 
are fine programs and all of their pro- 
grammers are to be congratulated for a 
job well done. Gambiet "80 would have 
destroyed the field in the original tour- 
nament. 

All of the programs in the field are very 
close in their playing ability, and that 
raises another interesting question. Are 
we approaching the theoretical limit to 
what can be done on a small computer? I 
don't think so. Before the end of the decade 
there will be a program on the TRS-80 
that plays 2000 level chess and will make 
Sargon II look as bad as Sargon made 
Microchess look. The programs to watch 
in the near future are Mychess. Sargon 
and Sfinks. □ 



TM 



ECHO SERIEb speech synthesizers 

COMPUTERS ARE SPEAKING OUT! 



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The ECHO H™ comes complete with speaker, instruc- 
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An all -inclusisc version o( this mem popular of card |un« This progiam both BILft and RATI 
either MM or duplicate bridge Der^istling on the contract, your computer opponents will either 
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provides challenging entertainmeni for advanced pUyen and is an excellent learning tool for the bridge 
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HEARTS 1.5 < Available foe ah com paters. MM S1S.W Caamut /WM IMafcette 

An eseit.ng and entertaining computer version of this popular card game Hearts is a trick-oriented 
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STUD rOKfcR (Atari o«l> > Met: Sll.WCaaamt /$IS.«9 Darnell* 

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POktKPAKIi (Available for allcumpulervl pftoKllT.fSCaaatiat/Ul.fSI 

POkl R PARTY i* a draw poker emulation based on the book. POKfcR. by Oswald lacoby This is 
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lhiv iv simply ihe best cribbage game available It is an excellent program for the cribbage Player -n 
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— " 



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number of guesses taken and by the difficulty of the board set-up 



CHESS MASTER ( North Star and I RS-M only I Price: $19.99 Caaaeue/$U.«5 IMaheur 

This complete and very powerful program provides five levels ol play It includes castling, en passant 
captures and the promotion of pawns Additionally, the board may be preset before the sian of play. 
permitting the examination of ••book" plays. To maximize execution speed, the program is written in 
assembly language (by SOFTWARE SPECIALISTS of California) fcull graphics are employed m the 
TRS-W version, and two widths of alphanumeric display are provided to accommodate North Star 
user*. 

MONARCH (Atari oairy) rrttv.*ll.tSCa»mt/$.9.99 Dasfcem 

M( INARCH is a fascinating economic simulation requiring you to survive an » year term a* your na- 
leader You deteimine the amount of acreage devoted to industrial and agricultural use. how 
■jajgt food to distribute to the populace and how much should be spent on pollution control You will 
find that all decisions involve a compromise and that n is not easy to make everyone happy 

CHOMP-OIHM.LO (Atari only) Price: SIIMCataette $15 .95 Dasfcelie 

( HOMP -OlHl 1 I Ol It's really two challenging game* in one CHOMP is similar in lonccpt to SIM; 
you must bite olt part of a cookie, but avoid taking the poisoned portion OTHfcLl O is the popular 
hoard game set i o fully utilize the Man's graphic capability It is also very hard to beat? This package 
will run on a I6K system 



DYNACOMP OFFERS THE FOLLOWING 



• Widest variety 

• Guaranteed quality 

• Fastest delivery 

• Friendly customer service 

• Free catalog 

• 24 hour order phone 



AND MORE... 



1 



STARTREK J.2 ( AvaHaMe for >l coaapatenl 



PrtC.: SII.M I atwrrteSIS « Ikwkelte 



Th,. .. iik dak lure* Wiiliii ln , bin ...h se>c..i ne» Imam fo. ..ample. .b« khngon, ..„- 

shoo, a. .he Lnle.pr.se without ...n.n, .hik also attacking st.rb.se, in other quadranls Ihe 

Khngor,, .ho ....ck .,.h boih lad,, -d heavy ,™» and mm+m shot * 7*5*^?"?*, 

.ben .he Tnle.ptive „ bes«ged by .h.ee be.., cruiser, and . ua.b.se SOS,. „.ei>ed Ihe kl.n.on. 
. ,n A N A L.O.O.. tOSoll«..e Cn.miie .nd Cme llllllll«lbl| 



F.nlerrm 
■e. e.ent See ihe wit 



BLACK HOI.K I Apple o«lyl 



M...IKIS.I 



i SU.M DUelle 



I „ u. mttm] |..phK.l .,mal..»o ol .he pfoblem. m.ol.ed in Ckrirt) ab«,.,n, . bl..k hole -,ih 
. ,p«:e piobe Ihe ob.ea ,. .o en.e. .nd minl.in. lo. . peeKiibed l.me. .« o.b.l cto« lo . >m.ll btock 
hole Thi. i. lo be Khiocd ...boo. com«.| w n«. .he m«™lr >h.l .he .,d.l M.e.s desuo,. .he piobe 
Cool.ol ol Ihe c.ll k ndMatH MmuUiled a..n f ode jell (o< .omion and main .h.uue.. lo. .. k ek.a 
inn Tbn piogtam employi Hi Rei ».«*« and » educ.lioo.1 u .ell .1 chdlen|in t 



Price: laSWO— iSllW OaJiHIe 

ro!!" ab.ll mlo.hokinlhe wicen Sound 



SPAt'K TUT ( Appk <mU> 1 

Uie Ibe ..me paddles to till Ihe plane ol the TV wieen iu iw . «.. -.« 

cimpk? NOI .hen the hok «et. cm.lk. .nd .m.lk.. A bodt in lime. .Ik... you to me.«i.e you. .koj 
.gainvi others in tin* habtl-Iormin* kikhi Mine 

MOVING MAZE (Appk u.l, I f*" '■* U ■>■■■■ <nU$mtmt 

MOVING MAZt employ, the i«ne, p.ddk> lo direct . puck Iron, one side of . mut u> the olhe. 
Ho.ese. the maje is dynamic.lly (.nd ..ndoenlyl btnll and is conlinuilly being modilied The obyec 
use ,, 10 c.ou .he maee ..thoul louchini lo. bein, hit by) a ..11 Scoiini n by » elap«d tune in 
dK.toi. and three k*eb ol pUy .re provided 

ALPHA Mlillim I Aim onl. I Price: 1I4.W CM -SSSA1 Ukkrm 

T.o eacellenl traphics and anion p.o»r.m. in one! ALPHA FICHIfcR ies.ui.es ,ou M destroy ihe 
al«n staishtps pas.ini Ih.oolh your vector of Ihe taluy ALPHA BASL is ,n .he pa.h ol an al«n LH1 
insasion. kl five UFOs gel b> and Ihe gune ends Bcxh games require Ihe loywck and gel progresii.e 
ly more difficult the higher you score! 

INTRUDER ALERT I Atari o.ly I I-*" ll».«4Ca.««./M».»5 DtakMle 

a tw pKed g.aphiss game .hich places you in Ihe msddk of ihe ■D.e.diur- h..ing |uu vlokn 
its pUn. The drosds have been .krted and .re directed lo deuroy you .1 all costs Vou muu lind and 
enter your ship lo ewape »nh the pkuii five levels of difficulty .re provided INTftUDtR ALLRT re 
quires . toyvltck .nd .ill run on ItsK systems 

(.IAN t SI.AMIM (Atari oaf, I Price: »l4.»5«a-«» $(• »"*"» 

Ihis leal lime .etion game is guaranteed addiclise! Use Ihe yoyuick to conliol ,our p.lh through 
slalom couises consisting ol both open and closed gam < hoose from d.fleient levels of difficult, . lace 
againsi other ptaycri or simply tike practice runs against the clock (HAM I SI AI <>M .ill run on Ink 
s, stems 

«, AMES P AC IS I ( A vaktabk lor al roaapattn) Mm BW CMtllgiJ^SJJglll 

GAMtSPACfs Iconuinslheclavviccompulergamevof Bl A< ts J At K.I l.NAR 1 ANDI-K. t RArs. 
HI 1RSI R Al I SWI It H and more These game, have been combined inlo one large program for ease 
in loading. The, are individually accrued by a convenient menu. This collection is .orth ihe pi ice iusi 
loi ihe DYNACOMP veruon of BLACKJACK 

C.AMES PACK II (A.aUaMr for al coaapalanl Prirr: SMWCaaaHH »M M Olakrti. 

GAMfSPACK II include. Ihe game. CRA/Y I -IGHIS. IOTTO, At I Y 111 l I Y. I III VVUMPUS 
and olbers As .i.h GAMtS PACK I, .11 the games ate loaded as one program and are called Irom a 
menu. You .41 particularly enjoy DYNACOMP". sersion ol t RA/Y LIGHTS. 
Why pay J7 »5 or mote per program when you can buy a DYNACOMP collection foe juu 110 «? 



MOON PROBE (Atari oary I Prir.:lll ISlaata SIS M Dtekett. 

Thii it .n e.lremcly chalknging "lunar lander" progr.m. The user must drop from orbil lo land al a 
predetermined target on the moon's surface You control the thrust and orientation ol ,oui craft plus 
direct the r.te ol descent .nd approach angk. 



ADVENTURE 

CRANSTON MANOR ADVENTURE(Nort» Slag a«ttCP/M only) Pttc: S2I M IXaactte 

Al tail! A comprehensise Adventure game lor North Star CRANSTON MANOR ADUN1I Kl 
takes you tnlo mysierious c RANSTON MANOR .here you .ilempt to g.thei fabulous ireasu.es 
1 u.k.ng in ihe manor .re »ild animals and lobois .ho .ill not gi.e up ihe ireasures .ithout a fighi 
Thr number of rooms is greater and the associated descriptions ate much more elaborale man ihe cut 
rem popular serie. of Adventure programs, making thi* game the lop in at cum Play can be stopped 
at an, lime and the status stored on diskette 



ABOUT DYNACOMP 

DYNACOMP » a leading distributor of small tyvlem software with takes spanning the work! 
(cunenlly in etcess of 40 counllin). Dutiim Ihe past two ycais we have (really enlarged Ihe 
DYNACOMP producl line, but have maintained and improved out high level of quality and 
cutlomct support The achievement in quality is apparent from our many repeal customers 
and the software reviews in such publications as COMPUTRONICS. HO Software Critique 
and A N.A.L.O.G. Out customer support is as close as your phone. It is always friendly 
The staff is hujhly trained and always willint to discuss products or five advice 



L 



•ATAKI. m. T/ISJO. NORTHSTAK. CP M aid IBM art t, t aurrd Irodtnomet tmdloi 

- —* 



••TRS-90 dukeitti art not %uppi*d w»a DOS or BASK 



BUSINESS and UTILITIES 

sniK.I ABI> ,M I< P Mniln »>*« «•».«»* 

SPtl I t.l ARl> it * r*,otulronary turn product -huh ikimmi ih« >a*u« of your current oord presetting inifm iV*t )KU 
STAR MAt.lt WAND lilt IRK Pt Nt |1 1 1 X II I> I DITOR II and othntl *i«i« rrmreii m aaternbty language 
M*l I Lt.l ARI> ,M raprdi, attnii in* uMi in rhmmatowj inching and iypo»rnpei.,al errori <>* coMfiwmf «Kti -otd of in* 
■*«i aga.au a dkHawf letpandabtfi of o**t 30.000 of ihc imm common tnghth -or at Word* appratMtg m th* km but not 
found mi in* dtcnonary air lUgMd' lot **„ ■dentificarton and correction Mow oommmraiii* uaff femrliar oah -ord pro 
ceiainn wnaawi nat bttMf io uvt SCI t H.t ARI>' M >a ™i» a le* mmom 

MAII MM 2 I (Am*. Ale^ne>dNr**1bNtMdn*«to*»tyl MmWJI 

I hit program it unmatched mi in abiuiy io uwt a iMiMwn numb** o( adder**, dm om dtakette iinm-num of I ill) p*t d«k 
Cti*. aon than «0D lot double denim hVRhnBatJ lit man, feature, include aaphabcl* and /* iod* tor ting. LaKcl prmung. 
merging of '•>«* and a untoa* keyword mama, routine -huh rfiiw.n enure, by a .trtuouy limtttet* tetavtron of inn drf mil 
code. Mail l«l J 1 -ill *v*n («d and d»t*t* duoticaie *niti*, A i«ty «*hmbt* program' 

FORM UTfta mm IMAM A**hr nod North Mm fatiW o*t*y I l*rt«e: Ml "5 

i -r II Mo create end edit I«™ letter, end addrr.. l.m lona brum art produced by etrtomat really mterimg each addren mi 
to a pe*d*termin*d portion ot your tenet II S it coencrt«i*ly crMifjaKibtr -ah MAII I I\t : 2. nhtch may be uwd lo manage 
tour addrei' Id*, 

M s and MAII UaTTU ate aiatlabkr at a combined package iwHit" 

vllHllliSonhSUraaKl r*rt l*a*JI DbAem 

NOB I IT it a general pt.rpo»* tor. program »nn*n m B0RO atvrmN, Language Ih.t program .41 wx, cruuen.ial data die, 
aen»iat*d b, NORTH STAR BASK Pnmoiy and optional urcondew, key* may t>» mimik or om lo nine character tiring, 
SORT 1 1 .t rawly utrrt -eh filet generated by OYNAt liMn MAII 1 1ST program and ■* »«ey tmntir* mi it, .eprrothiie, lo« 
all iMhn BASK, data 14* toiling 

PIRNOVAI HVAMr SySII M f AlM*M^ Nc** S«MMa*»l ****** W4.M DtWMf* 

PI S ,i a tingle ditk menu o««m<*d tvtiem coohpoatd of 10 program, deigned to orgerurt and ,rmpMy your per tonal TaMaKn 
»*a. U t*i .rKlod* . lOOiraMMCtMMicapMMy. fan accctv J* opi««aJ uwr *o*n. data reir*.*! by a>o*-h, iOd* i* P*W. ■>» 
tNMatJ priNiang of r*pom. ^tMNkbook bttlaocwt. ba* s iaph ptotiMa and Ntor* Aaw protated on ibc Auri dnkctM it ATARI 
DOS J 

IM i ommi \k AiimiAiaffiw*J»i r*n-.m.nm*m 

ThM tofi*ar* fMKkaja) cMMautt a m«t»d*i»*n toBrctMM of proffaina for faobUtMaj *fr»:WM l*o-*ay c n MWiKMw 
IM«a«k a full d«pk» modem Mmuu*d for WW] ka om Mod* of ofarratKM yon may coNMact lo a data mtvk* it i Ih* 
S<H Rt. t or MkioNMl a«d otwkry load d«U mkD m Mock «wMU»m Ma yowl dtUrtir for law »■*-»( TWt grwly I* 
dw.*t "cmw lay**" aMl ihot th* i*iv*r Lhara* Too may alto ranwd ih* comphrw cotMU of a toaaxMiKMioMt wmw 
• ItoiiiaiRj amajtiTi --"r- -f""' .rOBIRAN.ru ma» he N»« ..If tm* ui.n« -h* »up*«ri i*«! ed-»r and lai*r "«p- 
loMM'' lo alMMbcr cortifMMcr. mak«« ih* Atari a ►*»? iMan KimmI !:*«• Alar. BASK proraM> My It* u*4oaded Fw 
■Mi. a [■mm in it f * may be bwh off hM and «t*d laMt at toMioBMg micmm for a teat uwr* iy urm n* it. yon ian wt up 
yoM MlfiMIP* of imm tnarr .iwnmand. and profliMit. and the Atari *tR uantmi 
adek up lo ta>m« both commki urn* aMl yotw urn* 

DVNACOMrai»OM»r»|Mrt THI UWMIM1 A f()R --h an Atari IKJ modem f 
aiairli for SIM M 



p*K*ottJI«*1 Tmm 



IHIMHIIHtllKPMl |h,a« : m*4Dlr**m«J«0»- 

lh.t.i*h*t*vo-diektaiet.iHo*..inVNA(OMI'ip.T«U- 11 XI I l»l IC >R I and ^miami many n*. lealuirt »nh UXI 
t DITOB 1 1 toy ma, tnatld MR filrt « clMMkt and atiembr* Ihrm lor laMt drtpU. Bhxht of UU may b* apomdrd. inimrd or 
dvtfttd ti*niMyMid«do*idtMj dttknt* m tifM iL.it.rvd vmirted formar io be lar*t praMM by «h« TtXT E-tMtOR II 
oiih«(t MIOIai.l.iy r i*lh*i . A St I It P M fdrt (MKhadaat BASK aMl aja—My hll M Ml M prorjfMWt irwiT b* »**d by Ih* 
editor and protrttrd In faci. t*.t f.kt can be budi yong H> and tairr formatted uung II XI IIMIOB II All m all II X I 
I UllOB II .i an wnanwr. *aay lo ut*. bui vrt> llrnbk rdrtmi tyurm 

<<>MPItKVS(SMlfcSIMM»r,l P>t**:SUf4 

COMf BUSS n a twfkdnk MlriMy program -h*h ttMio aH ■■■* fm iry tpacvt and topOonaRy) R I Mark tiairmrnti from 
North Star BASK program. Th* tows* fit* it prot*uM) mmkni BBW. thM perm.ttmg i«ry large progiami lo be com 



DMIhVRMKtaly) 

Th- handy program aBo^ Monh Star inn io aaan 

.b K h rntar MjtMy ac<n«mola<*t DfILt ■ amy »o -It -*. aM) «• It ».U iMganu* .ow d.tki to protMte rff^rm. loxaimg o 



U IKMlll by keyword, of Ihrat iyp*t rrrtortai leg lau name). 



rchet for Ih* coranercwl >• 



lommmtal Mg pMmbnil and RrfrtrrK* teg mrajartM arncln. record afmamt. «ki I 
art Nrthdey. annnntary and appomraMM taMclM* U 
iordt Rrfererrce record, air atirt**d by a tuigt* kryord o 

I.RAMXtmvBiMrty. PrwIKMCaMa. til « Wah***. 

Ih.t M09M program aRo-t yon w Matty crMM grapR^i fkraclly from th* kryboard Von "draw yo-r flf w« utmg th* pro 
gram . menu t • cvrwr coMtoh One* ih* I«im* » made, a it aanomaucatty aapiaiirj io yow BASK program at a Mrmg *ai 
■aM* Dta- a -happy lac* . call n HI and ihm prmt rt from yoM program aaaag PBIMT M»' Th» » a ,*t» *aty •m»awt 
and tat* graphrci 



EDUCATION 



HfllM.r KMM.r ( Apple M»h. *•* Ai*4r»olt M 1*>let*f BASM I 
I rt HOCKrr Pt MX.I be yoar ihdd'i baby Rgfaj Ptnung any k*y on your 
prmng' rrlatrd to in* truer or numbrr of th* choten kry Th* program' 

Hun ran I Hot IKHK.I It >|rr.| .. a mm .ntinMdaung tcactMng d*i 



Prtta: »l«.*9 1 r— tie UJ.M} Dhybettt 
II rcaith m a diff«t*M and intriguing * hap 
cotor and townd air a I t hgBl 



IIAtHKP SPITHA,. 

Tn*» n Ifat r«u of DYNACTJMP-t cctucattonal pachagm Pramer** mwrnded * 
young ModtM *nh counttng practK*. leiivr wotd n 



r* til Mtrmwat* II* « II 
A io grade V It At HI RS PI 1 

a of malh ikdl uticim 



MOHsl tOllr IKAINrK.IHN-BBM.ry I 

MORStctHH IRAINIR.,d««tTW 

MCT it m td**J tofi-atr pachaa* for MC Met pracixr The cod* tayaavJ i 
u may ctrooa* the pitch of ih* ton*, at «*R at ik 
'. punctuatwn and alnnabri mil, at **U at lb* k 



Prtr* »ll*«ta*a*tt* SUMii 

d accuracy m daoflhafiat Moty* ( ode At inch. 
4 throagrh the rnrpnoM yack of any Man 
He Atao. *anovt mode, of opetaooa are 
om otm meiinge A .ety rfftcut* »iy io 



MISCELLANEOUS 



lAINfAiarrtMktyl 
k yjMMt* aajontbm randomly wodacet f< 

: hjannsp 



, % «Mf caaeaw ilS.WIhhfeeN* 
h u>n*t rrhrch ,ary a* the patwrat ar* 
vntnm«ruMg CRYSTALS hat beta 



NtMRTHMABMHIWAKI FXf HAM.I iNNNIillUARi 

DYNAtXlMP no* dmrmoiet th* 21 >otum* NSSt hhrary Tn«»« dnk*un rach c 

tlandtac «alo* for Ih* fntrchat* pt ur Ih*y thontd he part of every North Slat nan 

for detail, regarding ih* commit of th* SSSI coBrcuon 

Prate t*.«* *art ST *rt rach |4 or morel 

th* complrt* lOtkcuan may b* pnrchaied lor SIM •*, 



AVAILABILITY 



DYNACXMIP tofi-arr it tavfmad >Mb ■ 



mpln* d 



tpectr-yd all proarama -dl ran otthan laR program memory 
able on ATABl. PUT. TRSJ0 lLe»*l II) and Apcte (Aatytr 

H.blod.tknir Admt«naJly.a*oatprotrama- 

ng under MBAMt 



•mac* (ATABl raryarret J4RI Eacena 



Ml I' ' CP'M ftoppy dnki for 



STATISTICS and ENGINEERING 



IIM.IIAI Ml IIBiA.ae-tbarlorWicMa^oam! Prk* %n*Hmmm, Ul tS U 

DIGIT At 1-UTtR » a comprtttenaitc data procetwig program wbtch nrrmn ih* utct to detain hit otta F.lin I unci ton or 
.hoot* from a menu of filter form* The fitter 'omit ar* tubteouetuiy contcned into non ratvrtnr contohitton ^otf lueiwi 
*hn* ptrmri raprd data procrttrag In tM eaptKM orttga mod* in* Aap* of th* frcotrency irantlfi luikimn it tpecifrad by 
dn-ectly *m*r ing pomtt along th* dewred ftkar cor** In in* aaw mod* ideal lo* pan. high pa» and bandpatt fdlrri may b* 
aaprot— atr-d io . ar, mg orgrret according lo lb* Number of pomtt aatd in iM catcwlauoa Thet* (dim may optionally aho M 
taaoothed wan a Hannotg fumnon In addmon. moRi-waayr Buit*r»orth f.lim may be yenxied leatute. of DK.II M 
III II R intlod* plotting »l <h« data b*lore and ali*r i.Urrmg, at -ell at d.tptay ol rn* vhoten fitter fonciront Aliomchrdtd 



DAT A SM*JOTHUI iSaf ■' ■»■■ for Alorti Prkc* SM 

Thrt tpactal data vayoothmg program may be ut*d io rapidly dart** imrfvl mforttm ti oa from aot 
daia -huhar* actoalry tpac*d The toft— r* ferjtMet. cnott* m iagre * and tana* of fit, a* *»R a* tmooihad ftrw and 
dentMrtt cafcotartoa Alto .nckuded w amomm n pasttrng of in* mpui data and imoot h ad trwtv 

H H Kit R AN ALYUM I A*adJmMe (or nR i i gnilm l Prtr* SM M CRRaMBJ IM •§ 

Lt* Ihn program lo rtanunc th* franu rar y toattra of hmaeal duration u gnah The program (raiur*, auiomau, tcahng and 
plottmg of Ih* input data and rttwRt Prac ucal apRhcationt irwlud* Ihc analyn, of crjanfawcaarjd patiernt mi lack frrtdt at tare 



II AtlrnaWrrt.MIM Aararyrerl Prtee SlaMtaaarta* WtSU 

Thai it a tpacMd aofiwgre package oeach amy be ut*d to *,aaaaw Ihc iraraafrr function t of tywrmi toch at hi ft ampbftrri and 
Tdatrt by eiammmg thctr retponte to p-ttad mot*, 1 1 a it a ma tot mrjdriKMton of FOU Bll R AN Al i /t R and coniamt an 

laamirrini nnrnirR Itrrtrt mm trg 'ruiir- i rl " ii-fr Irt 'f—§ ' V*h*r*ni MH Rll R ANAI Y/l R >, d* 

tawed lot rdocauonnl aM) acieatilk nw. TTA w an n 



H ABMONK AN Al Y /IB I At aBaMt Cm nfl t imp ai m I Prtc* \U « ( anartat SIR M Ihahmr 

HARMtiNIt ANAI t/IR «ai drngn*d for trw tpmtrum anaryMt of r*M1Mrv* na*«tr>r*nt Nnurct aacntde data file genet* 
ttoa, tdrtMuj and uorag* retrieval aa t**R a* data and ipanmi ptoumg Om pattKumriy unMot faobiy n that ih* inpot data 
aaad not M royalty tpaced or at order The original data m tonad and a ctnYtc trait** mwpoftunm it oatd to creaa* in* data fd* 
raawa r ed by th* I IT nlgraeyihm 

toiRlf R ANAIY/tR. If A and HARMONIC ANAt YZEB may be imr rh iaad lag eth at for a caaMmaad prx* of SM W 
<thrae cateetiet) artd WW lihr** dnhtttet) 

RK.Itl VtM)N 1 1 Ataayayhe* for nB i ■■piliri) P",. si« *a, r-«« su t^utaa**** 

Rtt.RISSION I i, a tarrawn- and ««<«at i o*rnBy veraattle on* dn MM rMtal taaat trannret porynomud" c«,r frxuuj pr.. V ram 
Faataret mchid* tory hajh atotracy. aa autorraauc la y * * d m immatiwt oMton. an mctw*** tnternal horary of fwung I one 
two*, data adrtrng. aotomajbt data ami cmv* ptoumg. a wauttnal anarytn leg wandaid drcnuon. correhnton .netfiiteM. 
mitadnnk more In nddtuon. net* l*i may he triad oahoM inrnarrmg in* data « t t.RISMtiN | „ cenamty tk* corMr 



KH.KINSMIN IIIPAKAIIIHA 
PAR AMI it denned to handle tl 
ln>n Ih* utrr iimpt, int*rli 



trad PABAI IT for tl 

Ml 1 I II IN I AK KH .Kl NNHIN (Ml Bi (A 
MLRna 



_ theparamcurtlAfli, A(2i. etc I at omm mot* He 
artdptou*da,*>th RK.RlSSttiN I Lt* RfcCRISSKrN I for potynomtal ftumg. 




ANOVAfA ■■RllifwiBciRhRRl m t ry«tD»»)(« 

ta in* patt lit* ANOVA (anarytn of varinac*) prrxedur* hM bara knui*d to Ih* bug* mainlrn 
DYNACOMP hM brott«ht the Poater of th- method (o unaR tywemt Far moat OMtwual -ah ANOVA. ihc DYNACOMP 
toft-are pmkag* inchrdei in* I *ay. 2 -ay and N .ay eeooMar** Alan protydad are th* Yate, 2 K p factorial dctagnt for 
(hot* unfarrtdiar onh ANOVA. do not taorry Th* accontennydM RacMaMln t loa -at ontkM m a IMortal favhton fby a pro 
feaaet m th* tayhmttl and tervm at an eaccahM muodaycoen io iM wertatt Aoo3*agmayta« ANOVA Ha a 
b^iMaaa the data baa* iKhrded are t***ral com 

BASK sillMIIK Nl BiHIl IIMV VcanYRM I (Net a 

DYNACtYMP it the eachrtrw diunbutor lor th* tof i*axe hayad to the popular ant aWSK SraMti/a S 
by f R»kd*tchd (,** the BY TT Mc<na- HOI na>*nmteanM m BYTt magartn*. Jamrnry lfBlt TMM a 
ggBM accordmg io d 



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J. M. Graetz 



I. BEFORE SPACEWAR! 

The Lensman, The Skylark, and Ihe 
Hingham Institute 

It's Kimball Kinnison's fault. And Dick 
Seaton's. Without the Gray Lensman and 
the Skylark of Space there would be 
nothing to write about. So most of the 
blame falls on E. E. Smith, but the Toho 
Film Studios and the American Research 
and Development Corp. have something 
to answer for as well. If Doc Smith had 
been content designing doughnuts, if 
American-International Pictures had stuck 
to beach blanket flicks, if (most of all) 
General Doriot hadn't waved money in 
front of Ken Olsen in 1957. the world 
might yet be free of Spacewar! 

It all came together in 1961 at the 
Hingham Institute, a barely-habitable 
tenement on Hingham Street in Cambridge. 
MA. Three Institute Fellows were involved: 
Wayne Wiitanen. mathematician, early 
music buff, and mountain climber; J. Martin 
Graetz (which is me), man of no fixed 
talent who tended to act superior because 
he was already a Published Author; and 
Stephen R. (Slug) Russell, specialist in 
steam trains, trivia, and artificial intelli- 
gence. We were all about 25 (the more or 
less to be the same). 
At the time, we were crashing and 

J. Martin Graetz, SO Mnulton Rd.. Arlington, MA 

02174. 



banging our way through the "Skylark" 
and "Lensman" novels of Edward E. Smith. 
PhD, a cereal chemist who wrote with the 
grace and refinement of a pneumatic drill. 
These stories are pretty much all of a 
piece: after some preliminary f oof a raw to 
get everyone's name right, a bunch of 
overdeveloped Hardy Boys go treking off 
through the universe to punch out the 
latest gang of galactic goons, blow up a 
few planets, kill all kinds of nasty life 
forms, and just have a heck of a good 
time. 

In a pinch, which is where they usually 
were, our heroes could be counted on to 
come up with a complete scientific theory, 
invent the technology to implement it. 
build the tools to implement the technology, 
and produce the (usually) weapons to blow 
away the baddies, all while being chased 
in their spaceship hither and thither 
throughout the trackless wastes of the 
galaxy (he wrote like that) by assorted 
Fenachrone. Boskonians. and the World 
Steel Corporation. 

Is that enough to turn the mind to 
margarine? It is not. In breaks between 
books, we would be off to one of Boston's 
seedier cinemas to view the latest trash 
from Toho. In the days before Mazdas 
and Minoltas. the Japanese (and occa- 
sionally the British and Californians) 
churned out a steady diet of cinematic 
junk food of which Rodan and Godzilla 
are only the best known examples. These 
movies depended for their effects on high 
quality modelwork. oceans of rays, beams, 
explosions and general brouhaha, and the 
determined avoidance of plot, character. 



or significance. They were the movie 
equivalent of The Skylark of Space. 

If that's the case, we asked ourselves, 
why doesn't anyone make Skylark movies? 
Hearing no reply (our innocence of current 
film technology, economics, and copyright 
laws as enormous), we often passed the 
time in the Hingham Street common room 
in deep wishful thought, inventing special 
effects and sequences for a grand series 
of space epics that would never see a 
sound stage. Nonetheless, these books, 
movies, and bull-sessions established the 
mind-set that eventually led to Spacewar! 

When Computers Were Gods 

In early 1961 Wayne. Slug, and I. by no 
coincidence, were all working at Harvard 
University's Littauer Statistical laboratory. 
A large part of our jobs was to run statistics 
computations for various Harvard persons. 
The agent of choice for this work was an 
IBM 704. 

To a generation whose concept of a 
computer is founded on the Z80 chip, it 
may be hard to visualize a 704 or to 
comprehend the place it held in the public 
imagination (along with UNIVAC) as the 
type specimen of what a computer was: a 
collection of mysterious hulking gray 
cabinets approachable only through the 
intercession of The Operator. In the 
specially built computer room. The Oper- 
ator set switches, pushed buttons, and 
examined panels of flashing lights, while 
his Assistants attended various whirring, 
clanking, and chattering devices, rushing 
to and fro with stacks of cryptically-printed 
paper, decks of weirdly-punched cards. 






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Space War, continued... 

and reels of recondite brown ribbon, all 
to the background hum of The Machine. 
Add a little incense and a few candles, 
and you could be forgiven for thinking 
these were the rites of some oracular 
shrine. 

Everything about the 704, from the 
inscrutable main frame to the glowing 
tubes (yes. tubes!) in the glass walled core 
memory case, proclaimed that this was a 
Very Complicated System operated only 
by Specially Trained Personnel, among 
whom programmers and other ordinary 
mortals were not numbered. In short, a 
computer was something that you simply 
did not sit down and fool around with. 

A Stone's Throw From Olympus 

In the summer of 1961 I went to work 
for Professor Jack B. Dennis, who was 
then the proprietor of the TX-O. a machine 
that to me was only slightly less legendary 
than its ancestor. Whirlwind. The TX-O 
was transistorized, and while solid-state 
computers were beginning to appear on 
the market, the "Tixo" was the original. 
Even in 1961 it was acknowledged to be a 
historically important research facility: 
many of the programs developed on the 
TX-O. such as Jack Dennis's MACRO 
Assembler and Thomas Stockham's FLIT 
debugging program, were the first of their 



kind. So the chance to work on this 
computer was in many ways a rite of 
passage; it meant that I had joined the 
ranks of the Real Programmers. 



A computer was 

something that you 

simply did not sit down 

and fool around with. 



While hardly your average populist 
Apple, the TX-O was definitely a step 
away from the Computer-As-Apollo. 
Instead of being sealed into its own special 
chapel, it sat at one end of a typical large, 
messy MIT research space. With its racks 
of exposed circuitry, power supplies and 
meters, and its long, low L-shaped console, 
the TX-O looked for all the world like the 
control room of a suburban pumping 
station. And the thing of it was. you were 
expected to run it yourself. 

So here was the former 704 Operator's 
Assistant pushing buttons, flipping switches, 
and pressing keys to make his own pro- 
grams work. In some ways it was simpler 



than the 704; for one thing, there wasn't a 
battery of clanking mechanical monsters. 
The TX-O's input and output medium 
was something called a Flexowriter: an 
all-in-one keyboard, printer, paper-tape 
reader and punch, that worked like a 
mule and had a personality to match. 
There was also a 'high-speed" paper tape 
reader, a Grand Prix whiz that could read 
programs into memory almost as fast as 
the cassette-tape reader on a TRS-80. 

And the TX-O had a Scope. Now 
console-mounted, programmable CRTs 
were not unheard of at that time but they 
were generally slow, inflexible, and awk- 
ward to program. The TX-O scope on the 
other hand, was easy to use; you could 
generate a useful display with fewer than 
a dozen instructions. And if that weren't 
enough, there was a magic wand: the 
light pen. (The importance of these two 
devices can't be overemphasized; Ivan 
Sutherland used the scope and the pen to 
develop his original "Sketchpad.") 

That was the TX-O: the world's first 
on-line computer, and the training ground 
for the designers and programmers of later 
generations of hands-on machines. The 
first computer bums— hackers— were the 
products of this training; without it. and 
them, there would have been no Space- 
war! 



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58 



CREATIVE COMPUTING 







CIRCLE 143 ON READER SERVICE CARD 



Space War, continued... 

Tixo's People 

The users of the TX-O were a melange 
of students, staff researchers and professors 
with not much in common other than 
their need for large amounts of largely 
unstructured computer time. The feel of 
the place, however, was established by 
the hackers— mostly students, but including 
a professor or two— whose lives seemed 
to be organized in 18-bit strings. Many of 
them worked for Professors John McCarthy 
and Marvin Minsky in the Artificial Intelli- 
gence Group, an odd bunch (even by 
MIT standards) who seemed convinced 
that given enough random-access memory 
and a really fast cycle time you could 
model the cognitive parts of the brain 
and hey presto! a real thinking machine. 
Others worked for Professor Dennis, who 
presided over the use and development 
of the TX-O and more or less benignly 
kept a semblance of order. The man who 
kept it all running was a soft-spoken, white- 
haired gentleman. John McKenzie, the 
chief engineer. 

Out of this cloud of computer bums 
emerged the group that brought Spacewar! 
to the silver (well, light gray) screen: Dan 
Edwards (AI Group). Lisp specialist; Alan 
Kotok (TX-O staff), who wrote MIDAS, 
the successor to MACRO; Peter Samson 
( AI Group), who made the Tixo and PDP- 
1 play Bach; and Steve Russell and I. 

"You Mean That's All ll Does?" 

When computers were still marvels, 
people would flock to watch them at work 
whenever the opportunity arose. They 
were usually disappointed. Whirring tapes 
and clattering card readers can hold one*s 
interest only so long. They just did the 
same dull thing over and over; besides, 
they were obviously mechanical— at best, 
overgrown record changers— and thus not 
mysterious. The main frame, which did 
all the marvelous work, just sat there. 
There was nothing to see. 

On the other hand, something is always 
happening on a TV screen, which is why 
people stare at them for hours. On MIT's 
annual Open House day. for example, 
people came to stare for hours at Whirl- 
wind's CRT screen. What did they stare 
at? Bouncing Ball. 

Bouncing Ball may be the very first 
computer-CRT demonstration program. 
It didn't do much: a dot appeared at the 
top of the screen, fell to the bottom and 
bounced (with a "thok" from the console 
speaker). It bounced off the sides and 
floor of the displayed box. gradually losing 
momentum until it hit the floor and rolled 
off the screen through a hole in the bottom 
line. And that's all. Pong was not even an 
idea in 1960. (Note: Well, maybe not Pong, 
but something very much like it. Watch 
these pages.— DH A) 

The TX-O's counterpart to Bouncing 
Ball was the Mouse in the Maze, written 
by Douglas T. Ross and John E. Ward. 



Essentially, it was a short cartoon: a stylized 
mouse searched through a rectangular 
maze until it found a piece of cheese 
which it then ate. leaving a few crumbs. 
You constructed the maze and placed 
the cheese (or cheeses— you could have 
more than one) with the light pen. A 
variation replaced the cheese with a 
martini; after drinking the first one the 
mouse would stagger to the next. 

Besides the Mouse, the TX-O also had 
HAX. which displayed changing patterns 
according to the settings of two console 
switch registers. Well-chosen settings could 
produce interesting shapes or arrangements 
of dots, sometimes accompanied by 
amusing sounds from the console speaker. 
The console speaker is a phenomenon 
whose day seems to have passed. More 
than just a plaything, for the experienced 
operator the speaker was a valuable guide 
to the condition of a running program.) 

Finally, there was the inevitable Tic- 
Tac-Toe. with the user playing the com- 
puter. The TX-O version used the Flexo- 
writer rather than the scope. (The game 
is so simple to analyze that there was 
even a version for the off -line Flexo.) 

These four programs pointed the way. 
Bouncing Ball was a pure demonstration: 
you pushed the button, and it did all the 
rest. The mouse was more fun. because 
you could make it different every time. 
HAX was a real toy; you could play with 
it while it was running and make it change 
on the fly. And Tic-Tac-Toe was an actual 



game, however simpleminded. The ingred- 
ients were there; we just needed an idea. 

The World's First Toy Computer 

For all its homeliness, the TX-O was 
still very much a god. It took up lots of 
space, it had to be carefully tended, it 
took special procedures to start it up and 
shut it down, and it cost a lot of money to 
build. 

All this changed in the fall of 1961. 
when the first production-model PDP-1 
was installed in the "Kluge Room" next 
door to the TX-O. It had been anticipated 
for months; an early brochure announcing 
the machine (as well as a couple of no- 
shows called the PDP-2 and PDP-3. in 
case you were wondering about that) had 
been circulating in the area for a while. It 
was clear that the PDP-1 had TX-O genes; 
the hackers would be right at home. 

The -1 would be faster than the Tixo. 
more compact, and available. It was the 
first computer that did not require one to 
have an E.E. degree and the patience of 
Buddha to start it up in the morning; you 
could turn it on anytime by flipping one 
switch, and when you were finished, you 
could turn it off. We had never seen 
anything like that before. 

II. SPACEWAR! BEGUN 
The Hingham Institute Study Group On 
Space Warfare 

Long before the PDP-11 was up and 
running Wayne. Slug, and 1 had formed a 




The TX-O. 






60 



CREATIVE COMPUTING 



sort of ad-hoc commute on what to do 
with it — it being the Type 30 Precision 
CRT Display which was scheduled to be 
installed a couple of months after the 
computer itself. It was clear from the 
start that while the Ball and Mouse and 
HAX were clever and amusing, they really 
weren't very good as demonstration pro- 
grams. Why not? Zooming across the 
galaxy with our Bergenholm Intertialess 
Drive, the Hingham Institute Study Group 
on Space Warfare devised its Theory of 
Computer Toys. A good demonstration 
program ought to satisfy three criteria: 

1 ) It should demonstrate, that is. it should 
show off as many of the computer's 
resources as possible, and tax those 
resources to the limit: 

2) Within a consistent framework, it 
should be interesting, which means that 
every run should be different: 

3) It should involve the onlooker in a 
pleasurable and active way— in short, it 
should be a game. 

With the Fenachrone hot on our ion 
track. Wayne said. "Look, you need action 
and you need some kind of skill level. It 
should be a game where you have to 
control things moving around on the scope, 
like. oh. spaceships. Something like an 
explorer game, or a race or contest. ..a 
fight, maybe'.'" 

"SPACEWAR!" shouted Slug and I. as 
the last force screen flared into the violet 
and went down. 

The basic rules developed quickly. There 
would be at least two spaceships, each 
controlled by a set of console switches 
("Gee. it would be neat to have a joystick 
or something like that... "). The ships would 
have a supply of rocket fuel and some 
sort of weapon: a ray or a beam, possibly 
a missile. For really hopeless situations, a 




('inure 1. The Start- 
ing Position. The ships 
are in the centers of di 
■gonally opposite quad 
rants. The vee of stars 
top center is the horns of 
Taurus. You should he ahle to 
pick out the stars of Orion at the 
left I the hrii;ht star just ahove the 
wedweship is Riueh. 




Spacewar! was an 
appealing, simple 
concept, and the 
hackers were the 
appealingly simple 
people to bring it to life. 



panic button would be nice. ..hmmm.. .aha! 
Hyperspace! (What else, after all. is there?) 
And that, pretty much, was that. 

The Hackers Meet SPACEWAR! 

By the end of summer. 1961. Steve 
Russell had returned to the Artificial 
Intelligence Group (he'd worked there 
before Littauer); consequently, whatever 
ideas the Study Group came up with were 
soon circulating among the hackers. Space- 
war! was an appealing, simple concept, 
and the hackers were the appealingly simple 
people to bring it to life. First, however, 
there was the small matter of software. 

The PDP-1 was a no-frills machine at 
the beginning; except for a few diagnostic 
and utility routines, there was no program 
library. In a way this suited the hackers 
just fine: here was a chance both to improve 
on TX-O software and to write new stuff 
that couldn't have been done before. First, 
and fairly quickly. MACRO and FLIT 
were translated from TXish to PDPese. 
FLIT becoming the first in a continuing 
line of DDT on-line debugging programs. 
Steve Piner wrote a text display and editing 



program called Expensive Typewriter (For 
a while, "expensive" was a favorite adjective 
for naming various PDP-1 routines that 
imitated the functions of more mundane 
devices. Among them was Peter Samson's 
E. Planetarium, as we shall see.), another 
original whose lineage you can trace, if 
you like, right down to the latest word 
processors. 

With the software taken care of we 
could write real programs, which is to say 
toys. Bouncing Ball was successfully con- 
verted to PDP-1 use. but HAX. for some 
reason, was not. But no one really missed 
it, because we had a brand-new toy 
invented by Professor Marvin Minsky. The 
program displayed three dots which pro- 
ceeded to "interact." weaving various 
patterns on the scope face. As with HAX. 
the initializing constants were set in the 
console switches. Among the patterns were 
geometric displays. Lissajous-like figures, 
and "fireworks." Minsky 's program title 
was something like "Tri-Pos: Three-Position 
Display." but from the beginning we never 
called it anything but The Minskytron. 
("tron" was the In suffix of the early 
1960s.) 

The classic needle and wedge ship 
outlines and the opposite-quadrant starting 
positions were established at this stage, as 
shown in Figure 1. Acceleration was 
realistic: it took time to get off the mark, 
and to slow down you had to reverse the 
ship and blast in the other direction; the 
rocket exhaust was a flickering "fiery tail." 
Rotation, on the other hand, was by 
something we called "gyros"— a sort of 
flywheel effect invented to avoid consid- 
eration of messy things like moments of 
inertia. I guess they were really rotational 
Bergenholms. 

It was apparent almost immediately that 
the featureless background was a liability. 



61 



Space War, continued. 

It was hard to gauge relative motion; you 
couldn't tell if the ships were drifting apart 
or together when they were moving slowly. 
What we needed, obviously, were some 
stars. Russell wrote in a random display 
of dots, and the quality of play improved. 
The only thing left, we thought, was 
hyperspace, and that was on the way. In 
fact, we'd just begun. 



III. SPACEWAR! COMPLETE 

Please keep in mind that what follows 
did not happen in a neat first-one-thing- 
and-then-the next progression, but rather 
all at once in a period of about six weeks. 
When hackers are aroused, anything that 
can happen will. 

The Control Boxes 

Spacewar! worked perfectly well from 
the test word switches on the console, 
except that the CRT was off to one side, 
so one player had a visual advantage. 
More to the point, with two excitable 
space warriors jammed into a space meant 
for one reasonably calm operator, damage 
to the equipment was a constant threat. 
At the very least, a jittery player could 
miss the torpedo switch and hit the start 
lever, obliterating the universe in one big 
anti-bang. A separate control device was 
obviously necessary, but joysticks (our 
original idea) were not readily available 
in 1962. So Alan Kotok and Robert A. 
Saunders, who just happened to be mem- 
bers of the Tech Model Railroad Club, 
trundled off to the TMRC room, scrabbled 
around the layout for a while to find odd 
bits of wood, wire, bakelite. and switch- 
board hardware, and when the hammering 
and sawing and soldering had ceased, there 
on the CRT table were the first Spacewar! 
control boxes (Figure 2. These boxes have 
long since disappeared, but the sketch is 
a reasonably accurate reconstruction). 

First Steps 

By the end of 1961. all the elements 
were in place: a brand new. available 
computer, a cloud of hackers, tolerant 
when not actively implicated employers, 
and an exciting idea. Slug Rusell was getting 
the heat from everyone to "do something" 
about Spacewar! (I was in a different 
department at MIT by this time, and 
Wayne, alas, was one of those unlucky 
Army Reservists called to active duty during 
the Berlin Wall panic in October. He never 
got to participate in developing his own 
idea.) 

Russell, never one to "do something" 
when there was an alternative, begged off 
for one reason or another. One of the 
excuses for not doing it. Slug remembers, 
was. "Oh, we don't have a sine-cosine 
routine and gee. I don't know how to 
write a sine-cosine routine . . ." Then 
Alan Kotok came back from a trip all the 



way to Maynard (DEC headquarters) with 
paper tapes saying "All right. Russell, here's 
a sine-cosine routine; now what's your 
excuse?" "Well." says Slug. "I looked around 
and I didn't find an excuse, so I had to 
settle down and do some figuring." 

With the heavy mathematics in hand. 
Slug produced the first object-in-motion 
program in January 1962. This was nothing 
more than a dot which could accelerate 
and change direction under switch control. 
Even without a hardware multiply-divide 
capability (on the early PDP-ls. anything 
stiffer than integer addition and subtraction 
had to be done by subroutine) the computer 
was clearly not being pushed. 

From dot to rocket ship was a surpris- 
ingly easy step: "I realized" Slug says, 
"that I didn't have to worry about the 
speed of the sine-cosine routine, because 
there were only two angles involved in 
each frame— one for each ship. Then the 
idea of rotating the grid came out." The 
ship outlines were represented as a series 
of direction codes starting from the nose 
of the ship; when the ship was vertical 
and tail-down, each code digit pointed to 
one of the five possible adjacent dots that 
could be displated next. To display the 
ship at an angle. Russell calculated the 
appropriate sine and cosine and added 
them to the original direction code con- 
stants, in effect rotating the entire grid. 
With this method, the ship's angle had to 
be calculated only once in each display 



By February, the first game was opera- 
ting. It was a barebones model: just the 
two ships, a supply of fuel, and a store of 
"torpedoes"— points of light fired from 
the nose of the ship. Once launched, a 
torpedo was a ballistic missile, zooming 
along until it either hit something (more 
precisely, until it got within a minimum 
distance of a ship or another torpedo) or 
its "time fuse" caused it to self-destruct. 

The box is wood with a Bakelite top. 
The two switches are double-throw; the 
button is a silent momentary switch. Their 
functions are as follows: 

a. Rotation control. It is pushed to the 
left to rotate the ship counterclockwise, 
to the right to rotate clockwise. 

b. A two-function control. Pulled back, 
it is the rocket accelerator; the rocket 
continues to blast as long as the switch is 
thrown. Pushed forward, the switch is the 
hyperspace control, as described below. 

c. The torpedo button. It had to be 
silent so that your opponent could not 
tell when you were trying to fire. (There 
was a fixed delay between shots "to allow 
the torp tubes to cool" and fire was not 
automatic; you had to keep pushing the 
button to get off a missile.) 

With the control boxes players could 
sit comfortably apart, each with a clear 
view of the screen. That, plus the carefully 
designed layout of the controls, improved 
one's playing skills considerably, making 
the game even more fun. 




Figure 2. The original control boxes looked something like this. The 
controls arc al riuht-k-ft rotation, bl acceleration {pulled hack) and hyncrsna'.e 
(pushed forward I. and cl torpedo hotton. 



frame. The outline codes were kept in a 
table so that different shapes could be 
tried out at will, but this meant that the 
table had to be searched every frame to 
generate the outline. As the game devel- 
oped, this arrangement proved to be a 
sticking point which we shall see. was 
neatly solved by Dan Edwards. 



The Stars of the Heavens 

One of the forces driving the dedicated 
hacker is the quest for elegance. It is not 
sufficient to write programs that work. 
They must also be "elegant." either in 
code or in function —both, if possible. An 
elegant program does its job as fast as 
possible, or is as compact as possible, or 



62 



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Space War, continued. 





Figure 3. The "CHS Opening." The ships turn slightly away from the star 
and fire a short rocket blast (note the needle-ship's exhaust) to net into a 
comci-type orbit, then rotate the other way to try shooting torpedoes at 
the opponent. 



Figure 4. "Warp-induced photonic stress emission." The Hyperspace 
Minskytron signature. 



is as clever as possible in taking advantage 
of the particular features of the machine 
in which it runs, and (finally) produces its 
results in an esthetic-ally pleasing form 
without compromising either the results 
or operation of the other programs asso- 
ciated with it. 

"Peter Samson." recalls Russell, "was 
offended by my random stars." In other 
words, while a background of miscellaneous 
points of light might be all very well for 
some run-down jerkwater space fleet, it 
just wouldn't do for the Galactic Patrol. 
So Peter Samson sat down and wrote 
"Expensive Planetarium." 

Using data from the American 
Ephemeris and Nautical Almanac. Samson 
encoded the entire night sky (down to 
just above fifth magnitude) between 22 
1/2° N and 22 1/2° S, thus including most 
of the familiar constellations. The display 
can remain fixed or move gradually from 
right to left, ultimately displaying the entire 
culinder of stars. The elegance does not 
stop there. By firing each displayed point 
the appropriate number of times, Samson 
was able to produce a display that showed 
the stars at something close to their actual 
relative brightness. An attractive demon- 
stration program in its own right, E.P. 
was "duly admired and inhaled into Space- 
war!" 



The Heavy Star 

Up to this point. Spacewar! was heavily 
biased towards motor skills and fast 
reflexes, with strategy counting for very 
little. Games tended to become nothing 
more than wild shootouts. which was 
exciting but ultimately unrewarding. Some 
sort of equalizer was called for. 






Russell: "Dan Edwards was offended 
by the plain spaceships, and felt that gravity 
should be introduced. I pleaded innocence 
of numerical analysis and other things"— in 
other words, here's the whitewash brush 
and there's a section of fence — "so Dan 
put in the gravity calculations." 



The star blazed forth 

from the center of 

the screen, its flashing 

rays a clear warning 

that it was not to be 

trifled with. 



The star blazed forth from the center 
of the screen, its flashing rays a clear 
warning that it was not to be trifled with. 
Its gravity well encompassed all space: 
no matter where you were, if you did not 
move you would be drawn into the sun 
and destroyed. (As a gesture of good will 
towards less skillfull or beginning players, 
a switch option turned annihilation into a 
sort of hyperspatial translation to the "anti- 
point." i.e., the four corners of the 
screen.) 

The star did two things. It introduced a 
player-independent element that the game 
needed: when speeds were high and space 
was filled with missiles, it was often sheer 
luck that kept one from crashing into the 
star. It also brought the other elements of 
the game into focus by demanding strategy. 

64 



In the presence of gravity both ships were 
affected by something beyond their control, 
but which a skillful player could use to 
advantage. 

The first result of this new attention to 
strategy was the opening move in Figure 
3, which was quickly dubbed the "CBS 
opening" because of its eye-like shape. It 
took a while to learn this maneuver but it 
soon became the standard opening among 
experienced players, as it generally 
produced the most exciting games. 

The addition of gravity pushed Space- 
war! over the edge of flicker-free display. 
To get back under the limit. Dan Edwards 
devised an elegant fiddle to speed up the 
outline display routine. 

In Russell's original program, the outline 
tables were examined and interpreted in 
every display frame, and essentially redun- 
dant operation. Edwards replaced this 
procedure with an outline "compiler," 
which examined the tables at the start of 
a game and compiled a short program to 
generate the outline for each ship. This 
dramatically reduced calculation time, 
restoring the steady display and making 
room for the last of the original bells and 
whistles. 



Hyperspace 

While all this was going on, I was in my 
secret hideaway (then known as the 
Electronic Systems Lab) working on the 
ultimate panic button: hyperspace. The 
idea was that when everything else failed 
you could jump into the fourth dimension 
and disappear. As this would introduce 
an element of something very like magic 
into an otherwise rational universe, the 
use of hyperspace had to be hedged in 



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CIRCLE 121 ON READER SERVICE CARD 



Space War, continued. 



some way. Our ultimate goal was a feature 
that, while useful, was not entirely reliable. 
The machinery, we said, would be "the 
Mark One Hyperfield Generators . . . 
hadn't done a thorough job of testing . . . 
rushed them to the fleet" and so on. They'd 
be good for one or two shots, but would 
deteriorate rapidly after that. They might 
not work at all ("It's not my fault. ChewieD 
or if they did, your chances of coming 
back out intact were rather less than even. 
Slug: "It was something you could use. 
but not something you wanted to use." 

The original hyperspace was not that 
elegant. "MK I unreliability" boiled down 
to this: you had exactly three jumps. In 
each jump your ship's co-ordinates were 
scrambled so that you never knew where 
you would reappear— it could be in the 
middle of the sun. You were gone for a 
discernible period of time, which gave 
your opponent a bit of a breather, but 
you came back with your original velocity 
and direction intact. To jump, you pushed 
the blast lever forward. 

Hyperspace had one cute feature (well, 
I though it was cute). Do you remember 
the Minskytron? One of its displays looked 
very much like a classical Bohr atom, 
which in those days was an overworked 
metaphor for anything to do with space 
and science-fiction. Reasoning that a ship 
entering hyperspace would cause a local 
distortion of space-time resulting in a warp- 
induced photon icstress emission (see how 
easy this is?). I made the disappearing 
ship leave behind a short Minskytron 
signature (Figure 4). 

Crocks and Loose Ends 

In retrospect, it is remarkable that the 
original Spacewar! managed to include 
so many features, given the limitations of 



our PDP-1 : 4K words (about 9K bytes) of 
memory, an instruction cycle time of five 
microseconds, and a subroutine multiply- 
divide. It's hardly surprising, then, that 
we had to let a few unsatisfactory (all 
right, inelegant) bits go by. 

The most irritating of these (and the 
first to be improved in later versions) was 
the appropriately-named Crock Explosion. 
Something dramatic obviously had to 
happen when a ship was destroyed, but 
we were dealing with a plain dot-matrix 
screen. The original control program 
produced a random-dot burst confined 
within a small square whose outlines were 
all too discernible (Figure 5). 

This explosion was intended merely as 
a place-holder until something more plaus- 
ible could be worked out, but after all the 
other features had been "inhaled," there 
wasn't room or time for a fancier calcula- 
tion. 

Similarly, the torpedoes were not quite 
consistent with the Spacewar! universe 
after the heavy star was in place. The 
gravity calculations for two ships was as 
much as the program could handle; there 
was no time to include half a dozen missiles 
as well. So the torpedoes were unaffected 
by the star, with the odd result that you 
could shoot right through it and hit 
something on the other side (If you weren't 
careful getting round the Star, it could be 
you.) We made the usual excuses . . . 
mumblemumble photon bombs mumble- 
mumble . . . but no one really cared. 

The heavy star itself was not entirely 
Newtonian. The common tactic of plunging 
down the gravity well to gain momentum 
by whipping around the sun (Figure 6) 
gave you somewhat more energy than 
you were really entitled to. As this just 
made the game more interesting, nothing 
was immediately done to correct it. 



IV. AFTER SPACEWAR! 

The game was essentially complete by 
the end of April. 1962. The only further 
immediate work was to make Spacewar! 
presentable for MIT's annual Science Open 
House in May. A scoring facility was added 
so that finite matches could be played, 
making it easier to limit the time any one 
person spent at the controls. To provide 
for the crowds that we (accurately) antic- 
ipated, a large screen laboratory CRT 
was attached to the computer to function 
as a slave display. Perched on top of a 
high cabinet, it allowed a roomful of people 
to watch in relative comfort. 

Also in May, the first meeting of DECUS 
(Digital Equipment Computer Users' 
Society) was held in Bedford, MA. At 
that meeting I delivered the first paper on 
the subject, pretentiously titled "SPACE- 
WAR! Real-Time Capability of the PDP- 
1." 

Over the summer of 1962. the original 
Spacewar hackers began to drift away. 
Alan Kotok and I went to work for Digital. 
Steve Russell followed John McCarthy to 
Stanford University. Peter Samson and 
Bob Saunders stayed in Cambridge for a 
while, but eventually they too, went west. 
Dan Edwards remained with the AI group 
for a few years, then moved to Project 
MAC. Jack Dennis and the PDP-1 also 
wound up at Project MAC. which evolved 
into MIT's Laboratory for Computer 
Science. Others took up the maintenance 
and development of Spacewar! Program 
tapes were already showing up all over 
the country, not only on PDP-Is but on 
just about any research computer that 
had a programmable CRT. 

A Mystery, Just For Good Measure 

Slug tells me that there is a Lost Version 
of Spacewar! There would be, of course. 




Figure 5. The Crock Explosion. Nobody's perfect. 



Figure 6. A common mid-game flourish and don"t ask about G-forces! 



66 



CREATIVE COMPUTING 






He says the game is pretty much like the 
original, but the scoring is much more 
impressive. After each game of a match, 
cumulative scores are displayed as rows 
of ships, like a World War II fighter pilot's 
tally. Slug says he saw this version for a 
short time on the PDP-1. but never found 
out who produced it or what became of 
it. 

Twenty Years Later 

The original Spacewar PDP-1 was retired 
in 1975 and put in storage at DEC's 
Northboro warehouse, where it serves as 
a parts source for the similar machine 
now on working display at Digital's Com- 
puter Museum in Marlboro. MA. At this 
writing. DEC engineer Stan Schultz and I 
are trying to put the original Spacewar! 
back into operating condition. So far. all 
attempts at finding the original control 
boxes have been futile; we will probably 
build replicas (the plastic Atari joysticks 
we have now got no class). 

Dan Edwards still works for the U.S. 
Government, developing computer security 
systems. Alan Kotok is still a consulting 
engineer with DEC. Peter Samson is now 
director of marketing for Systems Concepts. 
Inc.. in San Francisco. Bob Saunders had 
gone to Silicon Valley, where is an 
engineer-programmer for Hewlett- 
Packard. 

Jack Dennis is a Professor of Science in 
the Electrical Engineering Department at 
MIT. 

John McKenzie. the chief engineer, is 
retired, but over the past year or so has 
been helping to restore the TX-O and 
PDP-1 to life at the Computer Museum. 

And what of the Hingham Institute? 
Wayne Wiitanen has recently become a 
Senior Research Scientist at the General 
Motors Research Laboratory, where he is 
happily designing eyes for robots. Slug, 
after various adventures, is now a 
programmer-analyst for Interactive Data 
Corp. in Waltham. MA. I am reduced to 
writing for a living, but tend to act 
somewhat less superior therefore. 

Spacewar! itself has bred a race of noisy, 
garishly-colored monsters that lurk in dark 
caverns and infest pizza parlors, eating 
quaters and offering degenerate pleasures. 
I think I know a few former hackers who 
aren't the slightest bit surprised. 

Acknowledgements 

I was able to reach all of the original 
Spacewar! perpetrators, hackers and 
Hingham Institute Fellows alike. Not to 
mention Professors Dennis and Minsky. 
and John McKenzie. In addition. I am 
grateful to Marcia Baker. Professor F. J. 
Corbato, and Professor R. M. Fano. all of 
MIT. for help with dates and places, and 
other facts. The help was theirs; any 
mistakes are mine. D 

AUGUST 1981 




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PuTTJNq AdvENTURE 



AdvENTURE Games 



Robert Plamondon 

As the months go by, the Adventure 
games get flashier. Some offer color 
graphics, some have animation, some have 
realistic combat or fascinating puzzles. It 
shouldn't be long before they start to talk. 
There's a lot of glitter in Adventureland. 

The glitter is impressive: it's easily good 
enough to convince you to buy the pro- 
grams. But after you get them home, and 
play enough to wear away the freshness, 
many Adventure games swiftly lose their 
appeal. 

Role-playing games, such as Dungeons 
and Dragons and Runequest. have been 
known to hold the players' interest for 
long periods of time. Role-playing cam- 
paigns can continue indefinitely because 
they deal with the lives of fictitious 
characters, and a person's life rarely reaches 
a state where it can be said that he has 
"won." With new characters being intro- 
duced as the old ones die or retire, many 
role-playing campaigns have lasted for 
years. 

Most designers of Adventure games 
probably think that they have designed 
role-playing games. They're wrong. To 
see why role-playing is important, and 
where the Adventure games have failed, 
we need to examine role-playing itself in 
more detail. 

Role-Playing Games 

"Role-playing" is a term that may have 
been coined because "play-acting" doesn't 



^D b S?,r am ° ndon ' 667 SW l5,h S,ree <- Ccrvallis. 






sound very dignified. A role-playing game 
is a play-acting game: it's as if someone 
took childhood games like Cowboys and 
Indians, brought them indoors, added a 
rules structure and a referee, and turned 
the players loose to act out the parts of 
their favorite heroes. 



Role-playing games are 

popular for the same 

reason that novels and 

soap operas are 

popular. 



The players (that is. the players who 
aren't refereeing) have the comparatively 
simple task of playing a single role — that 
of an inhabitant of the fantasy world that 
the referee has created. 

This character can be anyone the player 
wants him to be. from a total alien to a 
simple "clone" of the player himself. Role- 
playing does not necessarily mean you 
are playing the part of someone unlike 
yourself; it means that you are playing 
the game from the viewpoint of the 
character, as opposed to the viewpoint of 
the player. 

The character is assumed to believe 
that he lives in "the real world." If the 
player bases his decisions on the character's 



70 



perception of "the real world." he is role- 
playing: if he bases them on loopholes in 
the rules, the experience of a dead char- 
acter, or the length of time since the 
game was saved, he is not role-playing. 
Role-playing games must allow the players 
to make decisions solely from "game-world" 
information, and should encourage it 
wherever possible. 

The referee, called the dungeon master, 
game master, moderator, or "the referee," 
is in charge of the game. He creates the 
scenario— a foul dungeon with evil mon- 
sters and wondrous treasures, a bandit 
lair to be leveled, or whatever his imagi- 
nation dictates. He supervises the creation 
of the players' characters. He gets things 
started, plays the parts of all creatures 
except player characters, settles arguments, 
and picks up the pieces when the Adven- 
ture is over. Being a referee is not an easy 
task. 

As attention is paid to characters and 
their roles, the campaign becomes more 
interesting, because people, even fictitious 
people, are more interesting than flashing 
cursors or plastic game counters. 

Role-playing games are popular for the 
same reason that novels and soap operas 
are popular: people like to get involved 
in other people's lives. That role-playing 
games usually deal with a heroic and 
romantic universe doesn't hurt a bit 
either. 

Do's and Don'ts of Role-Playing 

There are many things that must be 
done, and more that must be avoided, to 
make a successful role-playing campaign. 

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Adventure, continued... 

Features of a Good Campaign: 

Realism. Realism in role-playing games 
means that none of the events breaks the 
character's "willing suspension of disbelief." 
Players can accept magic and dragons as 
part of the background of the fantasy 
world. They can't accept worlds that turn 
upside down at night (causing those outside 
to fall up), outdoor human colonies on 
the surface of the sun. or personal clues 
displayed on billboards. Silliness like this 
makes the game seem empty and trivial, 
which is not the object most designers 
have in mind. 

Another aspect of realism involves 
suppressing the egocentric nature of the 
game. The game exists for the players; 
the campaign world generally has no 
significance beyond the game. But it doesn't 
have to be obvious. It is unrealistic at 
best, and disturbing at worst, to be involved 
in campaigns where the game universe 
revolves around a character's navel. Glaring 
artificiality is as unacceptable in a game 
as it is in a movie when the camera pans 
beyond the false fronts of the houses to 
show the emptiness behind the facade. 

Pace is a missing element in many 
Adventure games. The game should zip 
right along, giving new developments, 
details, and problems as frequently as 
possible. Most Adventure games grind to 
a halt every few minutes as the player 
looks for the one and only tool that will 
get him past an obstacle. 

In live games, the pace can often be 
increased by screaming. "Get on with it!" 
at the referee. In computer games, there 
is no such option. 

Flexibility is another big problem. If 
many problems had more than one solution, 
there would be more opportunites for 
original play, or at least the illusion of 
original play. As it is. most Adventures 
are an exercise in taking a number of 
steps in a predetermined order. Going 
wrong kills, and the game has to be started 
over, either from scratch, a saved game, 
or resurrection. This is called "learn by 
dying." 

One way to give more flexibility to a 
game is to allow items to be used for 
purposes for which they were not originally 
intended. Thus, a tree could be cut down 
with a sword (slowly), or a chair used as a 
shield. In the traditional role-playing games 
(that is. those that aren't played on a 
computer), this is a standard ploy. 

Allowing the use of objects for many 
tasks takes mo-re intricate program design, 
as the objects have to be defined in more 
general terms. The most common substi- 



<sn/Q'Dna^oiu& 



tution is to use tools for weapons and vice 
versa — swords are used as crowbars, 
wrenches are used as clubs, and rope is 
used for everything. 

Incentive is a vital ingredient. Adven- 
turing is a dangerous business for any 
character, and there needs to be some 
incentive to explain his willingness to risk 
his neck. 

Ignoring incentives renders the campaign 
meaningless; the player has no goal, and 
just wanders around aimlessly. What fun. 

The usual incentive is money. Treasures 
are placed at strategic points along the 
character's route, and they are supposed 
to stimulate his avarice enough to make 
him enjoy the game. 

Treasure by itself is meaningless, how- 
ever. If the character can't do anything 
useful with it. it's just so much dead weight. 
Most successful games, such as Risk. 
Monopoly, and Dungeons and Dragons, 
recognize this, and make their "treasures" 
useful. In Monopoly, money is useful for 
purchases and expenses; in Risk money 
provides armies; and in D&D. money can 
buy anthing. including love (well, love 
potions). 

Character Growth is beyond the scope 
of most Adventure games, but should not 
be overlooked as a possible feature. 
"Character growth" describes an increase 
in the abilities or power of a character— as 
opposed to an increase in wealth and 
possessions. In traditional role-playing 
games, growth occurs in the form of 



Character Growth is 

beyond the scope of 

most Adventure games, 

but should not be 

overlooked as a 

possible feature. 



increased strength — both in arms and 
magic, as well as connections in high 
places— the acquisition of land, armies, 
public office, trading fleets, and. most 
important of all. reputation and knowl- 
edge. 

A game in which the characters experi- 
ence true growth is very rewarding. The 
player is obviously getting somewhere with 
his character when he becomes an impor- 
tant local figure. The flavor of the game 
changes as a character becomes powerful; 
what was a life-and-death matter at the 
beginning of his career becomes a trifle, 
and bigger and nastier problems appear 
to challenge his abilities. 




Features of Poor Campaigns 

Too many puzzles. The worst flaw of 
Adventure games is that they are puzzle 
games, and nothing else. The player tries 
to solve a series of puzzles, and proceeds 
a little further each time he figures one 
out. 

The problem is that puzzles aren't very 
exciting. They are often interesting, and 
somethimes fascinating, but they're almost 
never thrilling. Excitement is one of the 
keys to an enjoyable game, and is an 
element in which Adventure games are 
woefully deficient. What is worse is that 
they tend to replace excitement with 
frustration: you no sooner solve one puzzle 
than you are presented with another. 

Adventure games need to present the 
player with a series of problems to be 
solved, otherwise there is no challenge. 
But there are more elegant ways of 
achieving this than with a puzzle string. 

Most of the difference between the 
puzzle game and the problem-solving game 
is that the puzzle game presents you with 
obstacles that are easy to overcome if 
you know the trick and place the difficulty 
in finding the trick. Once the situation to 
a puzzle is known, implementing it is 
trivial. 

Other games make the execution of 
the solution difficult. It may be obvious 
that the characters will have to build a 
bridge to cross a river. The knowledge 
isn't enough: they actually have to build 
the bridge — and any number of things 
may go wrong. 

The problem lies in the realization that 
it is easier to program simple, deterministic 
solutions (such as. "if he has the axe. he 
can carve a canoe"), than to deal with the 
more complex case, which depends on 
circumstances, method, and perhaps luck. 
This fact leads directly to puzzle games: 
not because puzzle games are superior, 
but because they are easy to program. 

The Puppet Fallacy. A deadly sin of 
Adventure games is the statement. "I'll 
be your puppet in this adventure. You 
type in any two-word English sentence, 
and I will follow your advice like the 



72 



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Adventure, continued... 

zombie I am."— not in those words, of 
course. 

The phrase. "I'll be your puppet" man- 
ages to destroy the possibility of role- 
playing in four short words. It emphasizes 
the fact that you're playing a game, rather 
than embarking on an adventure, it reduces 
the concept of role-playing to the manip- 
ulation of an inanimate object, and triv- 
ializes the entire game. 

This is often compounded by having 
the game narrated in the first person, 
with frequent queries of. "what shall I 
do?"— which often provoke an obscene 
response. 

Since most Adventures provide no 
opportunity for character creation, the 
best they can do is project the player into 
the campaign. The easy way to do this is 
to describe everything in the second person; 
that is. to preface descriptions with, "you 
see..." and prompt input with, "what do 
you want to do?" 

This does much to create the illusion 
of the player being inside the Adventure, 
which puts it on a more personal level 
than the "puppet" format, which gives 
the impression that the adventurer is a 
zombie who completes an instruction, jerks 
to a halt, and waits for the next com- 
mand. 

The "Monty Haul" Campaign. There 
are two facets to the Monty Haul campaign, 
which is named after the host of the TV 
show "Let's Make a Deal." 

The first is the assumption that, if some 
treasure is a good incentive, more is better. 
This leads to campaigns in which the weight 
of the jewels found is too much for the 
adventurers carry, or where world- 
destroying weapons are guarded by rats, 
freeing the large monsters to protect the 
powerful stuff. 

This is comparable to the phenomenon 
of score inflation in pinball. It used to be 
that the least significant targets were only 
one or two points, and scores of four or 
five thousand were fantastic. Now the 
minimum score seems to be around a 
hundred, which means that there are two 
gratuitous zeroes tacked on the end of an 
honest pinball score. 

People are not fooled by this kind of 
inflation for long. Worse yet. you eventually 
exhaust their ability to conceive of large 
numbers. A score of a billion is meaningless, 
other than to give the impression of 
hugeness. An adventurer with world- 



shattering magic is rarely a person; he is a 
walking equipment list, and the equipment 
is too mind-boggling to be used seriously 
or well. 

The second facet of the Monty Haul 
syndrome is the choice of "Door Number 
One. Door Number Two. or Door Number 
Three." Many game designers delight in 
putting buttons to push, levers to pull, 
and other items to manipulate, with no 
clue to their function. The idea is that 
risking you character's life for no apparent 
purpose is fun. 

The proper method of dealing with 
machines of unknown (but probably dan- 
gerous) function is to leave them alone, 
as any eight-year-old can tell you. If the 
Adventure forces you to push the buttons, 
or whatever, then the correct response is 
to return the program to the manufacturer 
and ask for a refund, since the Adventure 
is obviously defective. 

If the purpose of the machine is known, 
then it is something less than perverse to 
confront the adventurer with unlabeled 



An adventurer with 

world-shattering magic 

is rarely a person. 



controls. For example, caterpillar tractors 
have many control levers which are often 
unlabeled. Trying to control the motion 
of a bulldozer would require some experi- 
mentation with the controls. On the other 
hand, the levers on a bulldozer won't cause 
steel doors to close in another building, 
or launch ICBMs— they affect only the 
bulldozer. Controls should be limited to 
reasonable functions. 

The Gilded Hole Campaign. This is the 
bane of Dungeons and Dragons campaigns. 
A common misinterpretation of D&D is 
that it consists of killing the monsters and 
taking their treasure. Why do the adven- 
turers do this? So they can afford more 
equipment to kill more monsters and take 
their treasure, etc. I'm not saying that all 
D&D campaigns necessarily fall into this 
trap— mine certainly don't — but it is one 
of the favorite misinterpretations. 

In the Gilded Hole campaign, the only 
places of any importance are places where 
monsters can be killed (and their treasure 



74 



taken), and places to sell the loot. Many 
campaigns consist solely of dungeons and 
general stores, with all other elements of 
a complete fantasy world discarded as 
irrelevant. 

The problem with this approach is that 
the endless struggle becomes boring and 
repetitive. After a while the monsters begin 
to look alike, and treasure fails to warm 
the players' greedy hearts. The Gilded 
Hole expeditions are simply too much 
alike to keep the players' interest alive. 

Besides, the treasure is supposed to be 
used as an incentive for action. In the 
Gilded Hole campaign, treasure is neces- 
sary for continued action, but not useful 
for any other purpose. All you can do 
with the loot is finance another expedition. 
No true incentive exists. 

If the money could be used to buy 
mansions, castles, or titles, or finance 
commercial ventures and private armies, 
the campaign would retain its appeal. It 
would also expand beyond the confines 
of the dungeon and general store, as the 
players tried to manage their other hold- 
ings. 

The Gilded Hole is an excercise in futility, 
since the struggle gets you nothing but 
more struggle. There are several Gilded 
Hole Adventures, some very well written, 
but they all suffer from their own limited 
scope. 

Gilded Hole campaigns link up naturally 
with Monty Haul campaigns, and the result 
is a very flashy, very poor. game. The 
flashiness is enough to make it sell, but 
not enough to make up for the flaws. 

Cuteness. It is difficult to enjoy an 
Adventure game in which the designer 
decided to be cute. Cuteness is generally 
an attempt at humor that failed. It destroys 
realism, crushes any semblance of signifi- 
cance and has a tendency to cause the 
player to sneer at the Adventure. Genuine 
humor is rarely harmful, but it's also rarely 
found. If a joke is called "cute," "silly," or 
"clever." by players, it should be buried 
as soon as possible. 

Opportunities for Role-Playing 

Opportunities for role-playing are rare 
in most Adventure games. All contacts 
with other creatures are superficial; if 
they speak, they just read off a pre-recorded 
speech, and if they fight, they attack with 
mindless ferocity. 

Role-playing can be exercised anytime 
there is a decision to be made, since the 

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Adventure, continued... 

role-player will try to make it in character. 
Still, most Adventure games have only 
one solution to each problem; there is no 
room for originality or personalization. 
The puzzle game and the role-playing game 
are mutually exclusive, since in the first 
the task is to find the solution, while in 
the other the task is to find a solution that 
suits the role you are playing. Puzzle games 
force the players to abandon their roles if 
they want to win. and give little room in 
which to play a role in any event. Role- 
playing games generally lack the inter- 
locking network of puzzles, and concentrate 
on the characters and their careers. 

Conversation with Creatures in the 
scenario has been avoided in Adventure 
games, perhaps because it's "too hard." 

That conversation is difficult in the 
format of two-word commands is obvious, 
and the equally obvious solution is to 
abandon the use of two-word commands, 
at least in conversation. 




Here is an example of what we might 
be able to expect from a future adventure 
game (computer output in all capitals): 
AS YOU WALK DOWN THE ROAD. A 
HUGE BANDIT LEAPS OUT IN FRONT 
OF YOU. HE POINTS A PISTOL AT 
YOUR STOMACH AND SAYS WITH 
A GRIN. "STAND AND DELIVER." 
"How much do you want?" 
(Note: quotation marks tell the program 
that the character is speaking) 
HIS GRIN WIDENS. "I AM NOT A 
GREEDY MAN," SAYS HE. "BUT I'LL 
TAKE WHAT'S IN YOUR PURSE. AND 
THAT FANCY DAGGER. TOO, AND 
LEAVE YOU THE REST." 
"Just the dagger" 



"I'LL HAVE BOTH, IF YOU PLEASE. 

AND BE QUICK ABOUT IT." 

Give purse 

(Note: the lack of quotation marks indicates 

a command) 

"MUCH OBLIGED, NOW THE 

DAGGER." 

Stab thief 

WITH A STRANGLED MOAN. THE 

BANDIT FALLS TO THE GROUND. 



Role-playing can be 

exercised anytime 

there is a decision to be 

made, since the 

role-player will try to 

make it in character. 



There is already a program which does 
a good job of providing realistic responses 
to English sentences; it is "Eliza." which 
is a convincing imitation psychotherapist. 
The program only recognizes a limited 
range of inputs, but that's nothing new to 
Adventure games. The Eliza algorithm, 
or a similar one, should be well suited to 
onversations in Adventure games. 

Watch the Role-Playing Games 

Adventure games have a distinct resem- 
blance to role-playing campaigns run by 
relative novices. Many of the advanced 
concepts, such as the nature of realism, 
character development, and other role- 
playing philosophy are either poorly done 
or ignored completely. 

This probably stems from the program 
designers' lack of contact with the role- 
playing community. All aspects of role- 
playing games are examined, criticized, 
and altered with surprising regularity by 
the faithful. 

Adventure game designers, and the 
players as well, would benefit from listening 
to these discussions. Fortunately, there is 
no need to find a cave full of game fanatics 
to hear the news. There are several 
excellent publications that deal with the 
practice and philosophy of role-playing. 
The philosophy of role-playing is a more 
practical topic than it would seem at first 
glance; handling a role-playing game well 
requires that you understand what you're 
trying to do before you start putting rules 
together. 



Conclusions 

Although there is trouble in Adventure- 



land, there is a great deal of potential, as 
well. Many of the ideas needed for a 
second generation of Adventure games 
have already been worked out, and others 
will be developed as Adventure games 
progress. The excitement of role-playing 
games and the abilities of the micro- 
processor are too complementary to remain 
separate for long. 

So, with high hopes, I keep my silicon 
sword and my CTRL-Reset shield ready 
for my next excursion into Adventure- 
land. 

Some Role-Playing Publications 

Alarums <fi Excursions is a monthly 
Amateur Press Association Magazine (APA 
or apazine). which is a collection of uncut 
contributions from anyone who wants to 
submit a stencil. The quality varies from 
contributor to contributor, and from issue 
to issue, and the legibility is often poor, 
but this is one of the best sources for 
ideas in role-playing games. Price is $1.50 
plus postage, which costs $0.83 book rate, 
or $1.40 UPS. Send a check to Lee. and 
she'll send you A&E as long as your money 
holds out, and refund any remainder. Write 
to: Lee Gold, 3965 Alia Rd„ Los Angeles. 
CA 90066. 

Different Worlds is a bimonthy profes- 
sional magazine which covers the entire 
field, with a leaning toward the philosophy 
of role-playing. Many of the better apazine 
essays appear in DW eventually, and it 
contains much original material as well. 
DW costs $2.50 per issue, and $10.50 for 
a six-issue (one year) subscription. Write 
to: Different Worlds, P.O. Box 6302, 
Albany, CA 94706. 

Dragon is a monthly professional maga- 
zine, which deals mostly with role-playing 
games, but has pieces on other games as 
well. It covers the whole field, but is 
deficient in articles on role-playing phi- 
losophy. Dragon costs $3.00 per issue or 
$24 per year. Write to: Dragon Magazine, 
P.O. Box 110, Lake Geneva, WI 53147. 

The Wild Hunt is a monthly apazine 
which is about half as thick as Alarums & 
Excursions, and is offset printed rather 
than mimeographed, which improves its 
legibility immensely. TWH is more con- 
cerned with role-playing philosophy than 
A&E, and the average quality may be a 
bit higher. It costs $1.50 plus postage, 
which varies from issue to issue. Send 
Mark a check, and he'll send you TWH 
as long as the money lasts. Write to: Mark 
Swanson, 40 Bow St.. Arlington, MA 
02174. □ 



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Original Adventure in 32K 



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Robert A. Howell 



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A few months ago something new was 
added to my family. A 10-lb. 16" by 12" 
by 4" Atari 800 computer. Not only that, 
this new computer had no disk. That's 
right, no disk. Only a cassette recorder to 
save and load programs and 32K (32.768) 
bytes of RAM. After having spent 17 
years of my life talking to big computers 
with million of bytes of memory and 
unlimited disk space (well, almost unlimi- 
ted). I was understandably a little nervous 
about the usefulness of such a small 
computer. 

About this same time. I had just finished 
several weeks of lunch hours (half hours 
if my boss is reading this) doing some 
fantastic arm chair spelunking. Yes. I had 
become hooked on exploring that colossal 
underground cave where magic is said to 
work and others had found fortunes in 
treasure and gold! 

My large, friendly computer at work 
had been my eyes and hands guiding me 
past giant snake and dragon through scores 
Of rooms deep underground. I even tricked 
a troll. I was able to retrieve 15 magnificent 
treasures bringing them to the surface to 
be mine forever! Once in that cave it 
wouldn't let me give up. as I soon discov- 
ered, until finally, finally, many lost lunch 
hours (half hours if my boss is still reading 
this) later, every corner and dead end 
had been explored, a map of the cave was 
in hand and I had solved the original 
"Adventure." 

Then a thought came to mind. I promptly 
dismissed it as absurd. But the thought 
kept haunting me until it became a chal- 



Roherl A. Howell. 
NH 0.1051. 



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The schedule of shows will be 

1 Cleveland, Ohio — August 14-16 

2 Milwaukee, Wisconsin — August 20-23 

3 St. Paul, Minnesota — September 9-11 

4 Detroit, Michigan — September 24-26 

5 Pittsburgh, Pennsylvania — October 1-3 

6 St. Louis, Missouri — October 15-17 

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Note - Because of limited space availability, an early reservation is recommended to assure you of space. 



RAM Cram, continued... 

lenge. Could this tiny little 32K computer 
with no disk which I now owned— could 
it possibly handle "Adventure"? Would 
the original Crowther and Woods Adven- 
ture program fit into 32.768 bytes of 
memory? 1 had seen several versions of 
this program advertised which required 
at least one disk drive and 32K or more of 
memory, but none for my little one. Was 
my little computer really equal to the 
task, or was I just fooling myself? 

The challenge lay before me: get 
"Adventure" running in Basic on an Atari 
800 computer with no disk and only 32K 
bytes of memory. Little did 1 realize what 
1 was getting myself into when I accepted 
this challenge. A challenge that would 
certainly tell me if this new little addition 
to the family was really a giant in dis- 
guise! 

Have you ever spent your whole summer 
beside the swimming pool out back, with 
the tops of your hands, shoulders and 
knees burning up from the sun. never 
once getting your swimming suit wet? No? 
Well then, you have never spent the 
summer trying to cram "Adventure — 
messages and all -into 32K of RAM. I 
did. And to spare you the gruesome details, 
suffice it to say that I accepted the 
challenge and won! Just as it was time to 
close down the pool for the winter. "Adven- 
ture" was running on my big computer 
(never again to be called "little"). 

The messages and vocabulary were not 
as extensive as in the original, but they 
were there, along with the rooms in various 
colors (except the "all alike" maze where 
passages and dead ends were all black t. 
Almost everything from the original 
"Adventure" was included. 





AUGUST 1981 



Now I know what you just said. You 
said. "How did he do it?" Well if you 
didn't say that then you should have, 
because that's the purpose of this article. 
As a result of my programming effort, as 
well as missing out on a whole season of 
swimming. 1 learned many techniques for 
efficient use of memory in Atari Basic. I 
am going to pass these along so that you 
will never need to worry about the swim- 
ming season passing you by. 

Although my examples and techniques 
refer to Apple Basic and "Adventure" 
type programs in particular, most of them 
can be applied to any computer and to 
programming in general. Why purchase 
48K of memory and two disk drives, when 
in many instances 32K or less of memory 
is all you really need. Why bemoan the 
fact that the latest "GLOP" game from 
the pages of this magazine requires 10K 
of RAM and your computer only has 8K. 
Apply a couple of the techniques that 1 
am about to describe and you can probably 
get the program into 7K or less without 
losing a single feature! 

REMarks 

Although 1 realize that adequate docu- 
81 



mentation is often lacking in many pro- 
grams today, when memory is at a pre- 
mium. REMark statements must be sacri- 
ficed. A remark N characters long including 
imbedded blanks) occupies N+3 bytes if 
on the same line as another statement 
and N+6 bytes on a line by itself. Thus. 
REM's interspersed throughout a large 
program can waste a significant amount 
of memory. 

An alternative which 1 use successfully. 
is to keep the remarks separately on paper, 
refering to the line numbers in the program. 
As the program is developed and changed, 
these remarks are also updated. Then, 
when the program is finished, a good set 
of documentation is already available. Also, 
by maintaining an up-to-date set of remarks. 
I found I was able to debug the program 
much more quickly. I estimate I saved 
about 1000 bytes of memory by eliminating 
the REMark statements from my "Adven- 
ture." 

Line Numbers 

When a new line (with a new line 
number) is added to a program. 6 bytes of 
memory are required by the new line. 
When that same Basic statement is added 
lo an already existing line, only 3 additional 
bytes are required. Therefore. 3 bytes of 
memory are saved each time a new state- 
ment is added to a line which already 
exists. (Multiple statements per line are. 
of course, separated by colons.) To illus- 
trate the savings that can result, in my 
version of "Adventure" there are about 
720 individual Basic statements (not includ- 
ing DATA statements) but only 325 line 
numbers. This saves (720-325)*3 or 1185 
bytes of memory. 

Having written programs for many years 
using one statement per line. 1 was a little 
apprehensive about how difficult multiple 
statements per line would make program 
legibility and debugging. However. 1 found 
1 had no trouble whatsoever reading the 
program and working with it. even though 
the Basic statements were packed very 
tightly. 

Putting more than one statement on a 
line can cause problems if one is not 
careful, especially in a Basic that contains 
no ELSE capability. Consider the following 
example: 
100SUM=0 
110 FOR 1 = 1 TO 10 
120 IF A(I)>0 THEN SUM=SUM + A 
(I) 

130 NEXT I 

140 PRINT SUM 
One would be tempted to rewrite this 
sequence all on one line (with one line 
number) as follows: 

100 SUM=0: FOR 1 = 1 To 10: IF 
A(I)>0THEN SUM=SUM+A(I): 

NEXT I: PRINT SUM 



RAM Cram, contini 



However, this puts the NEXT and PRINT 
statements under the control of the IF. 
causing them to be executed only when 



statement line. Figure 1 lists these state- 
ments with an explanation of what happens 
to statements which follow each of them 
on the same line. 



Statement 



Statements following on same line 



DATA 

DIM 

END 

FOR 

GOSUB 

GOTO 

IF . . . THEN 

LIST 

NEXT 

ON aexp GOTO lineno-list 

ON aexp GOSUB lineno-list 



POP 
REM 

RETURN 
RUN 
STOP 
TRAP 



Never executed 

Always executed 

Never executed 

Always executed 

Executed upon RETURN 

Never executed 

Executed on condition true 

Never executed on condition false 

Always executed 

Executed when FOR loop is finished 

Executed if aexp is less than 1 or greater than 

the number of line numbers in the lineno-list 

Executed if aexp is less than 1 or greater than 

the number of line numbers in the lineno-list. 

otherwise executed upon return from the 

subroutine 

Always executed 

Never executed — treated as part of the 

REMark 

Never executed 

Never executed 

Never executed 

Always executed 

Figure I. 



the IF is true. This will produce incorrect 
results. The proper way to consolidate 
these statements is: 

100 SUM=0: FOR 1 = 1 TO 10: IF 
A(I)>OTHENSUM=SUM+A(I» 

130 NEXT I: PRINT SUM 

Statements after an IF should be placed 
at the front of the following statement, or 
on a line by themselves if the following 
statement has a branch to it from elsewhere 
in the program. Of course if the statements 
after the IF clause are to be executed 
only when the IF condition is true, then 
they must be left on the same line as the 
IF statement. 

Here is another example which sets X 
to 10 or 20 depending on the value of L- 
100 IF L=R THEN 400 
200X = 10 
300 GOTO 1000 
400X=20 
500 GOTO 1000 
This section of the program can be neatly 
condensed into two lines as follows (elim- 
inating one GOTO and saving 27 bytes)- 
100 X=10: IF L=R THEN X=20 
200 GOTO 1000 
Again, the GOTO 1000 must be placed 
on a separate line so it does not fall under 
the control of the IF statement. 

It may not be obvious what will happen 
when some statements in Atari Basic are 
imbedded in the middle of a multi- 



Make a similar table for your Basic by 
trying out each statement in a small test 
program. Then keep this table handy for 
reference when you are optimizing a large 
program. 

Another way to eliminate line numbers 
is by inserting a NOT in front of an IF 
condition. For example: 

100IFA=1 AND B>5 THEN 130 

110B=B-1 

120 GOTO 1000 

130 PRINT 
may be rewritten on two lines (saving 1 1 
bytes) as follows: 

100 IF NOT(A=l AND B>5) THEN 
B=B-l:GOTO 1000 

130 PRINT 
Here is a different example that may occur 
in a program: 

90 ON X GOTO 100.200.300.400 

100 T=0: GOTO 1000 
These two lines may be condensed onto 
one line: 

90 ON X-l GOTO 200.300.400: T=0: 
GOTO 1000 

eliminating line 100 and saving three 
bytes. 

There are many other ways that multiple 
statements may be squeezed onto one 
line in order to save memory. A program 
that does not already do this can probably 
be reduced to 75% or 50% of its original 
line numbers. Keep in mind however, that 



82 



a branch to a statement from elsewhere 
in the program requires that statement to 
be at the beginning of a line. Also, in 
Atari Basic this technique is limited by 
the length of a logical line which is equal 
to a maximum of three physical lines or 
120 characters. Greater savings can be 
obtained using Basics which allow more 
characters per logical line. 

Don't Use Constants! 

One of the biggest memory wasters in 
Atari Basic is the use of constants. Each 
occurrence of a numeric constant or a 
line number in a Basic statement is replaced 
by one byte pointing to the memory 
location where the value of that constant 
is stored. This value in memory is stored 
in internal binary form and occupies an 
additional 6 bytes regardless of the size of 
the constant. Therefore, each use of a 
numeric constant or line number in a 
statement requires 7 bytes of memory. 
This method of storing numeric constants 
is what would be expected. Now for the 
bad news. Since Basic is an interpreter 
(that is. every statement is kept in memory 
in almost its original form and decoded 
each time the statement is executed), when 
it encounters a constant in a new statement 
being entered in. it has no way of knowing 
if that constant was used before. Therefore, 
it just goes ahead and converts into internal 
binary form and stores it in memory again 
using another 7 bytes. 

Now. suppose a large program uses the 
constant (zero) 50 times. Then that one 
constant occupies 7 times 50 or 350 bytes 
of memory! Likewise, suppose line number 
100 is referenced in GOTO and IF...THEN 
statements 50 times throughout a program. 
That one line number also occupies 350 
bytes of memory. So we have 700 bytes of 
memory being used to store the two values 
and 100. Wouldn't it be nice if each new 
use of the same constant or line number 
would point to the memory locations where 
that value was stored the first time? 

Fortunately, there is a way to make 
that happen: by the use of variables in 
place of numeric constants and line num- 
bers. The first time a variable is used in a 
statement four things happen: 

1. The variable name is placed in a 
table in memory called the VNT (Variable 
Name Table). 

2. Six bytes of memory are allocated to 
store the value of the variable. 

3. Two additional bytes are stored in 
the VNT which point to the value of the 
variable in memory. 

4. One byte is placed in the Basic state- 
ment in place of the variable name. This 
byte points to the VNT. 

Thus N+6+2+ 1 or N+9 bytes of mem- 
ory are used to store the first occurrence 
of a variable name (where N is the number 
of characters in the name of the variable). 

CREATIVE COMPUTING 






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Atari graphics and sound stand in 
a class by themselves." 

David D Tbornburg 

Compute Magazine, November /December 

1 980 

"Its superiority lies in three areas, draw 
ing fancy pictures (in color), playing 

music, and printing English characters 

onto the screen. Though the Apple can 

do all these things. — 

Atari does them better." 

Russell Walter 

"i nderground What COTT 

Guide to Buying a " llctl ***" 

computer" are sa> 

Published 1980, g~> * 

SCELB1 Publications C.OITipUie 



What computer people 

are saying about 
Computers for people. 



The Atari machine is the most extraordi- 
nary computer graphics box ever made..." 

Ted Nelson 

Creative Computing Magazine, lime 1980 

so well packaged that it is the first per- 
sonal computer I've used that I'm willing 
to set up in the living room." 
Ken Skier, OnComputing, Inc. Summer 1980 

"...well constructed, 
sleekly designed and 
user friendly— expea 

iter OeOOle reliable equipment, 

1*^ ^ and strong maintenance 

g abOUt ^ and software .support. 

for people" Videoplay 

December, 1980 



liitniAloui.ili.Hit the ATARI" 800 "Computer 

first hand, ask your local computer dealer 

for a hands-on demonstration. 

Or call, 800-538 8547 ( In California 800 672 1404 I 



ams&o 







ATARI 



Computers for people: 

For further information write: Atari Inc., Computer Division. 1196 Borregas Avenue, Sunnyvale, CA 94086 

CIRCLE 1 14 ON READER SERVICE CARD 



RAM Cram, continued. 



Now the memory-saving aspect of this 
method comes into play with the second, 
third, etc. time the variable name is used. 
Each subsequent use causes only 1 addi- 
tional byte of memory to be allocated: 
the byte in the Basic statement that points 
to the VNT. Unlike when a constant is 
used, the 6 bytes of memory to store the 
value is not allocated over and over 
again. 

To use this method of replacing constants 
with variables, one other item must be 
considered. The variable being used must 
be initialized with the value of the constant 
it represents. The most efficient way to 
do this is with READ and DATA state- 
ments at the beginning of the program. In 
an initialization section, values are read 
in for all the variables which are being 
used to replace numeric constants and 
line numbers. 

A good rule of thumb to use in deciding 
whether or not to replace a particular 
numeric constant or line number with a 
variable is the following: If the same 
numeric constant or line number is used 
four or more times in a program, memory 
will be saved by converting it to a variable. 
If used three or fewer times, leave it in its 
original form. 

Of course, the more characters there 
are in the variable name and in the 
constant, the more memory will be used 
in the VNT (to store the variable name) 
and in the READ/DATA statements. 
However, the break between three and 
four occurrences seems to work in most 
cases. 

Now you are probably saying to yourself. 
"How can I possibly make any sense out 
of my program if I convert all the constants 
and line numbers to variable names?" And 
1 agree. If you can't distinguish between 
the constants and actual variables, then 
reading the program listing becomes 
difficult. 

Therefore, decide on a pattern for 
variable names which will be used to 
represent numeric constants and line 
numbers in the program and stick to this 
pattern. An example of what I use is found 
in Figure 2. 



Constants 


Variable Names 




1 to 9 

10 to 19 

20 to 29 


Z 

A to I 
A0 to A9 
B0toB9 


90 to 99 
100 to 109 


10 to 19 
AOO to A09 


etc. 


etc. 




Figure 2. 



Then for real variables which do actually 
vary. I use the names J through Y and 
names that contain all letters (such as 
AA. AB. OX. ZZ. etc.). This way 1 can 
always distinguish constants from variables. 
If the program uses negative and decimal 
constants, then establish a pattern for them 
also. 

Figure 3 is example of a program segment 
before and after the constant-to-variable 
surgery has taken place. 

Note, when a statement number on an 
IF.. .THEN is changed to a variable, a 
GOTO must be inserted (see line 60 in 
Figure 3). Other than this one exception, 
any place a numeric constant or line 
number can be used in an Atari Basic 
statement, a variable can be substituted. 
Also note line 40: even the dimensions in 
an array can be made variables, thus saving 
the memory that would be used to store 
the constant dimensions. 

Is it really worth the trouble to convert 
most of the constants and line numbers in 
a program into variables? In my "Adven- 
ture" program. I changed 58 constants 
and line numbers to variables and saved 
over 3500 bytes! This represents 12% of 
the free memory on a 32K Atari system, 
so the effort certainly paid off. The 
maximum number of variable names 
allowed in a single program in Atari Basic- 
is 128. This is as big as the VNT can get. 

Therefore, start with the numeric con- 
stants and line numbers that are used 
most often since these will result in the 



Before 



40 DIM COUNT (100) 

50 FOR J=l TO 100 

60 IF INT|RND(0)*10)+1 > 6 THEN 90 

70 GOSUB 250 

80 COUNT(J)=COUNT(J)+ 1 

90 NEXT J 



After 

10 READ A.AO.AO0.B5O.F.IO.Z 

20 DATA 1.10.100.250.6.90.0 

40 DIM COUNT (AOO) 

50 FOR J=A TO AOO 

60 IF INT(RND(Z)'A0)+A> F THEN 

GOTO 10 

70 GOSUB B50 

80COUNT(J)=COUNT(J)+A 

90 NEXT J 



Figure .?. 






84 



greatest savings. Also, instead of converting 
constants which are not used very often, 
consider that GOTO 9 can be changed to 
GOTO D+E. This will save changing the 
constant 9 into a variable if D and E are 
already defined to be 4 and 5 respectively. 
The constant 9 requires 7 bytes whereas 
D+E requires only 3. a saving of 4 bytes 
of memory. Use this technique of com- 
bining variables to replace constants that 
occur three or fewer times in a program. 
As can be seen, substitution of variables 
for oft-used numeric constants and line 
numbers can result in a substantial increase 
in memory available in a program. 

Numeric Arrays 

How much memory will the following 
statement use: 

10 DIM A(IOO). B(IOO). C(IOO). D(IOO). 
E(100) 

If your answer is 500 bytes, you are not 
even close. The above dimension statement 
will require over 3000 bytes of memory. 
Yes. 3000! Why? As we discussed earlier, 
numbers in Atari Basic are kept in memory 
in internal binary form occupying 6 bytes 
each. Therefore, each of the above arrays 
uses I(K) times 7 bytes of memory apiece, 
and 5 of them will take 100 times 6 times 
5 or 3(XK) bytes. When the memory space 
is tight, there are two rules to observe in 
using numeric arrays: 1. Keep their dimen- 
sions as small as possible. 2. Eliminate 
them whenever possible. 

There are several ways to eliminate 
numeric arrays. I will mention two of 
them: Convert them to strings, and store 
numeric data in DATA statements and 
access it with READ statements each time 
the data is required. 

In Atari Basic, strings must be dimen- 
sioned. In the statement : 

lODIMRSHOOl. Ril(X)i 
R as we now know occupies 600 bytes, 
but RS occupies only 100 because it is a 
siring I(X) characters long. Now suppose 
in an "Adventure" program there are 100 
rooms and the program keeps track of 
which rooms have been visited and which 
have not. Fach element of RUOOl would 
represent a room. R would be initialized 
to all zeros and when a room was entered, 
the corresponding element of R would be 
set to 1. Since each element of R holds 
only a or I. this same function can be 
accomplished with string RSlUX)) using 
approximately one-sixth the memory. First 
RS would be initialized to all "N" characters 
(representing "No. the room has not been 
entered") as follows: 

1(X) FOR 1 = 1 TO 100: RS(I.I)="N": 
NEXT I 

(Note in Atari Basic. RSli.j) represents 
the substring from RS starting with char- 
acter i and ending with character j. 
Therefore. RSri.il represents the ith char- 
acter of string RS.) Then when room 

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RAM Cram, continued 



number I is entered. R$(I.I) would be set 
to "Y" (indicating "Yes. the room has 
been entered"). At the end of the game, 
the number of rooms visited would be 
counted as follows: 

1000 SUM=0: FOR 1 = 1 TO 100: IF 
RS(I.I)='Y'THENSUM=SUM + I 
1010 NEXT I 

Of course, if a numeric array is needed 
to store many different values, this method 
will not work. However, for storing just a 
few different values, try using a string 
instead of a numeric array and substitute 
different characters for the various values 
in order to save on memory. 

Now suppose a program uses numeric 
data that never changes. The room move 
table in "Adventure" is a good example 
of this. My "Adventure" has 126 rooms 
and there are 10 possible directions to 
take out of each room <N= I. NE=2 E=3 
... NW=8. UP=9. DOWN= 10). If an array 
were used to hold this data, it would contain 
126 times 10 or 1260 elements. At 6 bytes 
for each element, this table would occupy 
7560 bytes or almost one-fourth of my 
32K memory. The data in this array would 
be room numbers to move into from each 
room. So for example, to move West 
(direction 7) from room 29. the contents 
of array element (29.7) would be the room 
number to move into going in that direc- 
tion. Zero of course would mean no path 
that way. 

This data never changes. Therefore it 
can be put into DATA statements, one 
DATA statement per room. 10 numbers 
(corresponding to the 10 directions) per 
DATA statement. Suppose the DATA 
statement for room number 1 is on line 
10001. room 2 on line 10002. etc. Also 
suppose variable DR contains the direction 
in which the adventurer wishes to go and 
RC the number of the nx>m he is currently 
in. Here is how the program would locate 
the room number to move into- 

100 RESTORE I0000+RC: FOR J=l 
TO DR: READ RN. NEXT J 
The RESTORE locates the DATA state- 
ment for room RC. the FOR loop reads 





until the room number corresponding to 
direction DR is read at the end of the 
loop. RN contains the desired room 
number. Using this technique. I saved 
about 3650 bytes of memory on the room 
move table in my "Adventure" program. 
To go even one step further. I put the 
data for rooms 1. 2 and 3 all on DATA 
statement 10003: rooms 4. 5 and 6 on 
DATA statement 10006 and so forth, thus 
eliminating two thirds of the DATA 
statements and saving another 600 bytes. 
The RESTORE statement will still work 
in Atari Basic because a RESTORE to 
line l(KX)l (for room 1) will actually start 
reading at line 10003 if lines 10001 and 
1(XK)2 do not exist. Of course, the FOR 
loop had to be modifed to read the correct 
set of 10 room numbers as now there 
were 30 room numbers per DATA line. 
With this modification, the room move 
table has now been reduced from 7560 to 
about 3300 bytes for a 56".. reduction in 
memory used. 

Furthermore, upon examining the room 
move table data. I found that it contained 
many zeros. This occurs because there 
are exits from most rooms in only a few 
of the 10 directions. Therefore. I replaced 
n consecutive zeros in the DATA state- 
metns with the number -n. For example, 
if one of the DATA statements contained 
8 zeros in a row. these zeros were elimi- 
nated and a single -8 put in their place. 
This was done in all DATA statements 
where 2 or more zeros occurred together. 
The read routine was then modified to 
expand negative numbers back to the 
original number of zeros as the data was 
read. This modification further reduced 
the room table from 3300 bytes to 2236 
bytes now occupying 70"., less space than 
if a 126 by 10 numeric array had been 
used. Thus, over 5300 bytes of memory 
were saved with several very simple 
modifications to the room move table part 
of the program. 

Since numeric data items require 6 bytes 
each when stored in numeric variables or 
arrays, if the data does not change during 
program execution, keep it stored in DATA 
statements and READ it when it is needed. 
Pack it on the DATA statements as tight 
as you can. Otherwise use string'arrays if 
possible. The fewer numeric arrays a 
program uses, the more memory will be 
available to it. 

Strings 

Although strings require less memory 
than numeric arrays, still try to keep their 
length to a minimum. Don't set up A$( 100) 
when the maximum length A$ will ever 
be is 50 characters. Also, eliminate string 
variables when possible. If three strings 
are defined in a program and one of the 
strings could do the functions of all three, 
eliminate two of them. 




86 



r!!WWimi.»»f»i,.iinl|Hy 

"Adventure" type programs always have 
a vocabulary of words which they recognize 
(NORTH. TAKE. DRAGON. INVEN- 
TORY. DIAMONDS, etc.). Cut these 
words down to their first five characters 
(NORTH. TAKE. DRAGO. INVEN. 
DIAMO. etc.) Although some games use 
the first four or three characters, five is 
about the minimum length which can be 
used and still make the words unique. 
When the player's input is received, each 
word of it is truncated to five characters 
before a search is done against the vocab- 
ulary in the program. 

As discussed previously with numeric 
data, place the vocabulary in DATA 
statements and READ it when it is required. 
In Atari Basic, strings are placed in DATA 
statements without quotes and are 
separated by commas. Since Atari Basic- 
does not have string arrays (e.g. A$(100) 
does not mean 100 strings, but defines a 
siring to be a maximum of I (X) characters 
long), to store the words otherwise, they 
would need to be packed into a string. 
Since the words are variable in length 
(INVEN is five characters long but TAKE 
is four. OIL. three, etc.). this would require 
extra program statements and overhead. 
With the vocabulary on DATA statements, 
it may be searched by READing it from 
beginning to end with a special character 
('. S. etc.) marking the end of the table. 

This will take a considerable amount 
of time, especially for words at the end of 
the table. Therefore, a more efficient way 
is to place all words beginning with the 
same letter in a separate DATA statement. 
Then a RESTORE is used, keyed off the 
first character of the word being searched 
for. to locale the DATA statement con- 
taining all words starting with this letter. 
As can be seen, putting both numeric 
and string data into DATA statements 
can be a very effective way to reduce the 
amount of memory required by a program. 
Before numeric arrays and strings are set 
up. consider the use of the READ/DATA 
statement technique. It may make the 
difference in being able to get a program 
into memory. 

Eliminate Unneeded Statements 

When you need to alternate a program 
variable between and 1 . how do you do 

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RAM Cram, continued. 



it'.' Before reading on. lake a piece of 
paper and write the Basic statements to 
set B equal to if its value is 1 and vice 
versa (keeping in mind that Atari Basic- 
does not have an ELSE capability). Now 
look at your programming. Is this the way 
you did it? 

10 IF B=() THEN B= 1 : GOTO 30 

20 B=0 
Or how about this way? 

10 ON B+ 1 GOTO 20: B=0: GOTO 30 

2()B=1 
Or better yet? 

I0ONB+1 GOTO20:B=-l 

20B=B+I 



I ntokenize The Program 

When Atari Basic places a statement 
into memory, it uses a "tokeni/.ed" form. 
That is. each Basic keyword, each 
arithmetic operator and each relational 
operator are replaced by a unique 1-byte 
code called a token. At the same time las 
previously discussedl. constants are placed 
in memory in internal form and variable 
names are placed in the VNT (Variable 
Name Table). This is the way Basic- 
interpreters work. Thus, they automatically 
provide some efficiency in their use of 
memory. 

Now. after a new program is entered 
into memory, typically a debugging phase- 
begins. The program is run and rerun 




Each of these methods is gotnl and will 
accomplish the task, but they all use two 
lines. Is there a way (without using ELSE) 
to write this code on one line? Yes there 
is. A little creative programming reveals 
the following method: 

IOB=ABS(B-li 

The first three examples require 52. 60 
and 53 bytes respectively: the last example 
only 20 bytes. The point here is. eliminate 
unneeded statements wherever possible 
to save on memory. 

1 found in my "Adventure" program 
that the statement: 

Z=B. GOTO 90 
occurred 16 times. So 1 did the obvious: 
kept the first occurrence of this statement 
and replaced the other 15 with a branch 
to the first one. Now I know I have just 
caused a program abort to occur in the 
mind of every structured programmer in 
the audience. Please note. I am not against 
structured programming. 

In fact. I encourage it along with good 
program documentation wherever possible. 
However, the preceding example saved 
90 bytes of memory. By doing this same 
thing with several other statements that 
occurred multiple times in the program. I 
was able to save another several hundred 
bytes. So use of this technique really paid 
off. 



(and rerun and rerun and rerun....! many 
times to find and correct as many logic 
errors as possible. In this phase, statements 
are added, changed, deleted, rewritten, 
etc. If the program is large, debugging 
may take many days or weeks. During 
this time a number of variable names which 
were once used in the program will 
probably be completely eliminated. Or a 
typing error may have caused the variable 
TB. for example, to be entered when T 
was supposed to be used. Later on. this 
error is discovered and TB is replaced bv 
T in the statement, thus completely elimi- 
nating the variable TB from the program. 
Sounds logical so far. doesn't it. However, 
something else occurs that is not immedi- 
ately obvious. When TB is replaced by T. 
Basic, being an interpreter, does not know 
that the variable TB has been completely 
eliminated from the program. Basic has 
no way of knowing that TB is now used in 
any other statement. Therefore. TB still 
occupies 4 bytes in the VNT and 6 addi- 
tional bytes of memory are still reserved 
to hold the value of TB. Ten bytes of 
memory are being used by TB. Multiply 
this by another 10 or 15 variables that 
may have been used in the program but 
have since been eliminated, and we find a 
hundred or more bytes of memory being 
wasted. 



"Well." you respond, "when I CSAVE 
the program onto tape and then CLOAD 
it back into memory, doesn't the VNT 
and related memory get cleaned up?" 

The answer to this question is "No." 
because ■ CSAVE causes the tokenized 
version of the program to be written onto 
tape and along with the tokenized program, 
the VNT anil associated memory are also 
written. One of the reasons CSAVE works 
this way is because the tokenized version 
takes much less time and tape to write 
out. Now when a CLOAD is done, the old 
VNT still containing the unused variable 
names and their associated memory is 
read back in unchanged. 

How do you eliminate the unused vari- 
ables from the VNT and free up their 
memory bytes? Simple. The program must 
be written out in its untokenized form. 
This is the form that is seen on the screen 
when the program is listed with the LIST 
command. In Atari Basic, this is done 
exactly like a CSAVE except the command 
LIST"C" is used. LIS'P'C" causes the 
program to be LISTed to cassette tape. 
The tape will be written with the untoken- 
ized version of the program only and not 
include the VNT nor any other values 
from memory. 

Note, this process will lake two to three 
times as long as CSAVE and require at 
least twice as much tape. The tape should 
then be rewound. NEW typed to clear 
memory (this is important to erase the 
old program dnd VNT I. and the untoken- 
ized version read back in with the command 
ENTER"C" (which works just like 
CLOAD). The untokenized statements will 
be read in one by one. relokenized and a 
new VNT constructed. Since the old 
variable names are no longer in this set of 
Basic statements on tape, they will not be 
entered into the new VNT. 

When I had finished debugging my 
"Adventure" program. I untokenized and 
retokenized it and gained 150 bytes of 
memory. This allowed me to add a few 
more vocabulary words that I had pre- 
viously eliminated for lack of space. Note 
also that a program should be untokenized 
and retokenized whenever an ERROR 4 




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RAM Cram, continued... 

occurs. Error number 4 means the VNT 
is completely full with 128 variable names. 
Of course, if the program actually has 128 
legitimate different variable names, then 
this method will not work and some of 
the variable names must be eliminated or 
combined into an array (which takes up 
only one slot in the VNT). 

Use of POP Statements 

When I finally had the "Adventure" 
program finished, there were 450 bytes of 
memory available after loading and 50 
bytes free after execution began. I felt 
the program was now bug-free and ready 
for the final test: my 10-year old son. 
David. But a strange thing began to happen. 
After David played for one or two hours. 
ERROR 2 would occur and the program 
would abort. Error number 2 means out 
of memory. This error would occur 
randomly after about an hour of play 
without restarting the game, and always 
at a different spot. How could this be? I 
had very carefully calculated that there 
should be at least 50 spare bytes of memory. 
I was puzzled. It took me a while to figure 
out what the problem was. but I finally 
found it. 

When a GOSUB is executed. Atari Basic 
puts the return address into a push-down, 
pop-up stack in memory. Then when the 
RETURN statement is executed, the top 
address is popped off of the stack and the 
computer returns control to the program 
at this address. Thus the stack is constantly 
expanding and contracting in memory as 
GOSUB's and RETURN'S are executed. 
Now suppose a subroutine branches else- 
where in the program, never executing a 
RETURN statement. The return address 
remains on the stack forever. This is exactly 
what was happening in my program. Every 
once in a while the program would exit 
from a subroutine without executing a 
RETURN. Each time this happened. 4 
bytes of memory remained on the stack, 
never to be released, and the stack 
gradually expanded until it had eaten up 
the 50 bytes of available memory. 

There are two ways to eliminate this 
problem. The most obvious is to exit from 
every subroutine via a RETURN statement. 
However, it is not always possible nor 
desirable to do this. Therefore, before 
branching out of a subroutine where the 
RETURN will never be executed, a POP 
statement should be inserted. This causes 
the stack to be popped up one time, and 
the return address removed, just as if the 
RETURN statement had been executed. 
The format of this statement is: 

100 POP 
In my program. I put several POP state- 
ments just before the INPUT statement. 
The program continually returns here to 
get the player's next response. Thus. I 




made sure at this point that the stack was 
completely empty. Executing a POP when 
the stack is empty acts like a do-nothing 
statement and does not cause an abort. 
This small modification solved the 
problem. 

One note of caution when using POP 
statements in Atari Basic: FOR loops are 
also placed on the stack. Therefore, if a 
program is in the middle of a FOR loop 
when a POP is executed, the FOR infor- 
mation may be removed from the stack. 
This will cause the program to abort with 
error number 13 (NEXT encountered with 
no matching FOR) when the corresponding 
NEXT statement is executed. The way to 
avoid this is to make sure POP statements 
are not placed within FOR loops, or to 
make sure that you know exactly what 
order FOR and GOSUB information was 
placed on the stack so it may be correctly 
popped off. Note also that branching out 
of a FOR loop without completely finishing 
the loop does not cause the stack to grow 
and waste memory like GOSUB's do. so 
one only needs to be concerned about 
this problem when branching out of 
subroutines without executing a 
RETURN. 




Message Text 

Approximately one half of the memory 
in my "Adventure" program is text consist- 
ing of room descriptions and messages. 
Since the original "Adventure" text is too 
large to fit. it had to be cut down. There 
are several way to do this. 



One way is to eliminate completely a 
number of the least used, least important 
messages. Another way is to delete some 
of the descriptive adjectives and/or change 
the wording so that the message is smaller 
but still retains its original meaning. 
Abbreviating, using contractions and 
substituting smaller words all help con- 
siderably. Here is an example: 

Original message: "You are in a complex 
junction. A low hands and knees passage 
from the north joins a higher crawl from 
the east to make a walking passage going 
west. There is also a large room above. 
The air is damp here." 

Abbreviated message: "You're in a 
complex junction. A low N pass joins a 
higher crawl from the E making a walking 
passage W. There's a large room above. 
The air is damp." Counting spaces, the 
message has been reduced by 28% from 
204 to 147 characters. 

Half of the room descriptions (63) begin 
with the 1 1 characters 'You are in" (includ- 
ing the space following the word in). I 
eliminated these words from the front of 
those 63 messages and modified the print 
message subroutine to print them if the 
first character of the message to be printed 
was not a capital letter. This resulted in 
another 600-byte savings. 

Message text is stored in DATA state- 
ments. Message number 1 at line 15010. 
message 2 at line 15020. etc. The start of 
a message is located with a RESTORE 
15000+NMO where N is the message 
number. Many of the messages extend 
onto multiple DATA statements. 

A special character which is not used 
anywhere else in the message text was 
placed at the end of every message. This 
character is detected by the print message 
subroutine telling it when the end of the 
message has been reached. Adding this 
single character per message was the 
simplest way to allow the program to 
determine the end of a message when the 
messages were variable in length. This 
method also uses the least amount of 
memory. 
With a little creative rewriting, the 



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7 DEPRSL Straightline depreciation 

8 DEPRSY Sum of the digits depreciation 

9 DEPRDB Declining balance depreciation 

10 DEPRDDB Double dec* inmg balance depreciation 

1 1 TAXDEP Cash flow vs depreciation tables 

12 CHECK2 Ptints NEBS checks along with daily register 

13 CHECKBK1 Checkbook maintenance program 

14 MORTGAGE/A Mortgage amortization table 

15 MULTMON Computes time needed for money to double, triple. 

16 SALVAGE Determines salvage value of an I n ves tm en t 

1 7 RRVARIN Rate of return on investment with vanable inflows 

18 RRCONST Rate of return on investment with constant inflows 

1 9 EFFECT Effective interest rate of a loan 

20 FVAL Future value of an investment (compound interest) 

21 PVAL Present value of a future amount 

22 LQANPAY Amount of payment on a loan 

23 REGWTTH Equal withdrawals from investment to leave over 

24 SIMPDISK Simple discount analysts 

25 DATEVAL Equivalent 6 noriequiwtent dated values for oblig, 

26 ANNUDEF Present value of deferred annuities 

27 MARKUP % Markup analysis for items 

28 SINKFUND Sinking fund amortization program 

29 BONDVAL Value of a bond 

30 DEPLETE Depletion analysis 

31 BLACKSH Black Scholes options analysis 

32 STOCVALI Expected return on stock via discounts dividends 

33 WARVAL Value of a warrant 

34 BONDVAL2 Value of a bond 

35 EPSEST Estimate of future earnings per share for company 

36 BETAALPH Computes alpha and beta variables for stock 

37 SHARPE1 Portfolio selection model le what stocks to hold 

38 OPTWRTTE Option writing computations 

39 RTVAL Value of a right 

40 EXPVAL Expected value analysis 

41 BAYES Bayesian decisions 

42 VALPRMF Value of perfect information 

43 VALADfMF Value of additional informatjon 

44 OTTLiTY Derives utility function 

45 SIMPLEX Linear programming solution by simplex method 

46 TRANS Transportation method for linear programming 

47 EOQ Economic order quantity Inventory model 

48 QUEUE I Single server queueing (waiting line) model 

49 CVP Costvokjnievrci T t analysis 
50CONDPROF CorvdNJonal profit tablea 

51 OPTLOSS Opportunity loss tables 

52 FQUOQ Fixed quantity economic order quantity model 

NAME DESOUrTIOM 

53 FQEOWSH As above but with shortages permtded 

54 FQEOQPB As above but with quantity price breaks 

55 QUEUECB Coat-benefit wailing line analysis 

56 NCFANAL Net cashflow analysis for simple Investment 

57 PROF1ND Proftabilty Index of a project 

56 CAP1 Cap. Asset Pr. Model anafyils of project 



59 WACC Weighted average cost of capital 

60 COMPBAL True rate on loan with compensating bal required 

61 DISCBAL True rate on discounted loan 

62 MERGANAL Merger analysis computations 

63 FT1RAT Financial ratios for a firm 

64 NPV Net present value of project 

65 PPJNDLAS Laspeyres price Index 

66 PRMDPA Paasche price index 

67 SEASIND Constructs seasonal quantity indices for company 

68 TIMETR Time series analysis linear trend 

69 T1MEM0V Time series analysis moving average trend 

70 FUPRMF ' Future price estimation with inflation 

71 MAJLPAC Mailing list system 

72 LETWRT LeBer writing system*** with MAJLPAC 

73 SORT3 Sorts list of names 

74 LABELI Shipping label maker 

75 LABEL2 Name label maker 

76 BUSBUD DOME business bookkeeping system 

77 TIMECLCK Computes weeks total hours from timectock info 

78 ACCTPAY In memory accounts payable system storage permitted 

79 INVOICE Generate invoice on screen and print on printer 

80 rNVENT2 h memory inventory control system 

81 TELDK Computerized telephone directory 

82 TIMUSAN Time use analysis 

83 ASSIGN Use of assignment algorithm for optimal job assign. 

84 ACCTREC ri memory accounts receivable system storage ok 

85 TERMSPAY Compares 3 methods of repayment of loans 

86 PAYNET Computes gross pay required for given net 

87 SELLPR Computes semng price for given after tax amount 

88 ARBCOMP Arbitrage computations 

89 DEPRSF Sinking fund depreciation 

90 UPSZONE Finds UPS zones from zip code 

91 ENVELOPE Types envelope including return address 

92 AUTOEXP Automobile expense analysis 

93 riSITLE hsurancerjoacyfae 

94 PAYROLL2 ri memory peyroi system 

95 DILANAL Dilution analysis 

96 LOANAFFD Loan amount a borrower can afford 

97 RENTPRCH Purchase price for rental property 

98 SALELEAS SakHeasebeck analysis 

99 RRCONVBD investor s rate of return on convertable bond 
100 PORTVAL9 Stock market portfolio storage-valuation program 



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RAM Cram, continued... 

original "Adventure" message text was 
cut approximately in half so that it fit into 
14K to 15K of memory, but still retained 
its original meaning. The attractiveness 
of the game was not lost, and all of the 
excitement of the original "Adventure" 
was still there even though the messages 
were now in an abbreviated form. 



•S 



7A 



Miscellaneous 

Here are a few other hints for optimal 
memory use: 

1. Do not use long variable names (Atari 
Basic allows up to 120 character names, 
all characters significant). Each character 
in a variable name occupies 1 byte of 
memory in the variable name table. 

2. Replace IF X O with IF X (which 
is equivalent and saves 3 to 9 bytes 
depending on whether the is a constant 
or a variable). 

3. Use GOSUB's to eliminate multiple 
occurrences of identical program state- 
ments. 

4. Use as few variable names as possible 
by making them do double and triple duty. 
Rahter than use I. J. K. L. M and N as 
FOR loop variables, or Z0 through Z9. 
see if you can get along with using just I 
and J or Z 1 and Z2. The same applies to 



scratch variables and other variables in 
the program. 

5. Remove unnecessary parentheses and 
rely on operator precedence wherever 
possible (except, due to a known bug in 
Atari Basic, always enclose NOT and its 
associated variable in parentheses— (NOT 
B) instead of NOT B). 

6. Spaces may be used anywhere for 
program readability (except of course in 
strings). Spaces are not stored in memory 
when a program statement is tokenized. 

7. A new line always requires 6 bytes 
of overhead regardless of the size of the 
line number used. 

8. Change IF NOT (A=B and C=D 
and E=F...) 

to IF A <> B OR C <> D OR E <> F... 

Change IF NOT (A=B or C=D or 

E=F...) 

to IF A<> B AND COD AND 

E <> F... 

Memory will be saved in both cases. 

9. Use of the LET keyword does not 
cause extra memory to be allocated. It 
may be included or omitted as desired. 

10. The RUN command clears all simple 
numeric variables to zero and sets all strings 
to empty (length zero) so don't waste 
memory clearing them. However, numeric 
arrays are not cleared! If they must be 
initialized to zero, use a FOR loop (all on 
one line, of course). 

11. Many of the Atari Basic keywords 
can be abbreviated. Abbreviations have 
no effect on memory utilization. 



Memory Saving-Techniques 

Here is a summary of the memory- 
saving techniques discussed in the 
accompanying article: 

1. Eliminate REMarks. 

2. Pack multiple statements per line 
to eliminate numbers. 

3. Replace constants and line numbers 
with variables. 

4. Reduce the dimensions of and/or 
eliminate numeric arrays (convert to 
strings or use DATA statements). 

5. Keep strings small and put them 
on DATA statements. 

6. Eliminate all unnecessary state- 
ments, especially multiple copies of 
the same statement. 

7. Untokenize and retokenize. 

8. Keep the FOR/GOSUB stack from 
eating up memory. 

9. Reduce the size of message text. 

10. Use short variable names. 

11. Replace IF X <> with IF X. 

12. Use subroutines to eliminate 
duplicate statements. 

14. Eliminate unnecessary paren- 
theses. 

15. Rewrite to eliminate NOT. 

16. Don't initialize to zero excep- 
tion—numeric arrays). 



Summary 

Do these techniques really work? From 
experience I can emphatically say. "Yes 
they do!" Before applying these methods. 
I estimate the executable part of my 
"Adventure" program would have required 
26K bytes of memory. After optimization, 
it uses only 15K bytes, a 42% reduction. 
Likewise, the message text was reduced 
from roughly 24K to 15K. Thus I was 
able to get a SOK program running in 30K 
of memory for a 40% reduction in memory 
usage. With most unoptimized programs 
today, a 25% to 40% gain in memory can 
probably be realized with a little effort in 
applying some of these RAM cramming 
techniques. Thus, the savings can be sub- 
stantial! 

One last question lingers which must 
be answered: After optimization for 
efficient memory use with these methods, 
how slowly does the program actually run? 
When I had finished the "Adventure" 
program. I did find the response to the 
player's input to be too slow. It was in the 
five to ten second range. However, upon 
investigation I discovered that the program 
was taking five seconds searching the 
vocabulary list. The further down the list 
it had to search, the longer it took. 
Therefore. I did sacrifice some memory 
by placing words that start with the same 
letter together on separate DATA state- 
ments. Then I changed the search routine 
to do a RESTORE to the proper DATA 
statement keying off of the first letter of 
the word that was being searched for. 
This reduced the search from a maximum 
of 150 words to 20 or less. Also. I placed 
the most often used words at the beginning 
of each DATA statement. Thus the 
vocabulary is not packed as tightly onto 
DATA statements as it could be. However, 
with this one small change, response time 
is now in the one to two second range for 
most responses, with a maximum of five 
seconds for the GET/TAKE verb which 
has the largest number of program state- 
ments associated with it. It appears that, 
on the Atari 800. chaining constants to 
variables, reading from DATA statements, 
jumping all over the place with GOTO's 
and GOSUB's etc. doesn't cost the program 
too much in time. This, of course, may 
not be the case for a program that uses 
some of the fancy Atari sound and graphics 
capabilities. However, for "Adventure" 
in graphics mode (full screen text), the 
speed is adequate, even when a Basic 
program is highly optimized for memory 
usage. 

I encourage you to experiment with 
your computer. Try the things I have 
suggested. Discover some new techniques 
and then tell us about them. We are 
interested. As for me. now that I know 
what a powerful system I really have. 1 
am going to spend this summer actually 
swimming in the pool! □ 



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CIRCLE 135 ON READER SERVICE CARD 



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The New 
Man On-line 



In most industries contemporary 
parlance uses a nautical reference in 
speaking of new officers coming "on 
board." We don't think it has become an 
industry standard yet. but at least one 
computer company seems to have adopted 
a phrase more appropriate to its business: 
we were told recently that the new 
president of the Heath Company came 
"on line" in January 1981. 

We don't know what he was doing in 
his off line days, but we assume it was 
something significant, because Bill Johnson 
is familiar with the microcomputer industry, 
knows the position of his company in it. 
and has some very realistic plans for the 
future. 

In an interview at Creative Computing. 
Johnson cited a rapid increase in computer 
sales at Heath. The Heath Company, now 
a division of Zenith Data Systems, "hit a 
milestone in 1980 when it crossed the 
$100 million mark in sales." says Johnson. 
"Forty million of that was in computers." 

The Kit Business 

Despite projections indicating that the 
hobbyist market has reached saturation. 
Johnson sees no slowdown in the sales of 




Betsy Staples 



Heathkit computers. "I read all those things 
and love it— because people say 'don't 
get into that business.' " he says. 

"I would say that there is greater growth 
coming in the personal and business 
markets, because there are simply more 
of those people who have problems to be 
solved. But the hobbyists were the first 
people in. and I can assure you that our 
business is growing very healthily. Our 
computer business is growing at a rate in 
excess of 50% per year, and the kit side is 
participating fully in that growth. We are 
totally committed to serving the kit segment 
of the market." 

Heath's main claim to fame in the kit 
market. Johnson feels, is "our competence 
in writing construction manuals. We also 
have 57 locations around the country to 
hold the customer's hand and provide parts, 
etc." 

The Heath motto. 'We will not let you 
fail.' Johnson thinks, "feels warm and fuzzy 
to a lot of people." 



Bill Johnson. President of Ihe Healh Company. 

Assembled Side 

Before Heath was acquired by Zenith, 
company plans called for distribution of 
assembled Heath computers through retail 
computer stores and other outlets. After 
the acquisition, management quickly agreed 
to rename the division Zenith Data Sytems. 
"It partitioned the kit business away from 
the retail or assembled line better. I know 
if I were a small business man. I would 
feel better with a Zenith Data System 
sitting on my desk than a wired kit." 
Johnson explains. 

He adds. "I think we are perceived in 
the kit business as having good quality, 
design, etc., but I don't think that transfers 
particularly well to the assembled side." 

Is Zenith Data Systems an arms-length 
operation, or is it the same operation with 
a different nameplate? It's both. The new 
Computer Business Group, which designs 
products, seems to be the bridge between 
the two divisions. 

As Johnson explains it. once a product 
is designed, it can fall into either the kit 
or the assembled computer division, or 
both. The Computer Business Group also 
handles software for both divisions. Where, 
a year or two ago. Heath employed 16 or 



94 



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CIRCLE 167 ON READER SERVICE CARD 




17 hardware engineers and "a couple of 
software people." there are now 45 to 50 
hardware people and 37 or 38 software 
people "with open requisitions for at least 
another 15 if we can find them." 

Software 

There are obviously many fewer second 
sources (independent producers) of soft- 
ware for Heath/Zenith machines compared 
to those who write for other popular 
computers. To what does Bill Johnson 
attribute this? 

One of the reasons, he thinks, is "the 
perceived lower base of products in the 
field." However, he cites two recent surveys 
which list Heath/Zenith as number three 
in the U.S. 

"Another thing is that in the beginning 
we marched off to our own drummer 
with HDOS— our own operating system— 
and with our own bus and some other 
things that, if we had to do over again, we 
probably wouldn't do that way." 

Heath currently has three levels of soft- 
ware support. Languages and operating 
systems carry the Heath label and are 
documented in the "full Heath style." Heath 
also supports HUG. the Heath Users' 
Group, to the extent that the company 
provides a means by which programmers 
can exchange original and public domain 
software. 



Between these two levels is quality 
applications software bearing the SoftStuff 
label. Most of the programs in the SoftStuff 
line are polished, documented versions of 
programs submitted by users who receive 
royalties from Heath. 

In addition. Zenith Data Systems has 
recently announced the availability of four 



Heath will continue to 

offer high technology 

items in kit form. 



software packages for the Z-89. WordStar. 
MailMerge. DataStar and SuperSort. all 
of which run under CP/M. are being 
offered under a license agreement with 
Micro Pro International. 

What's Ahead for Heath 

"I think that the position that Heath 
has in the marketplace fits in with the 
image Zenith has of itself and its future." 
Johnson says. "We know that we are in 
the television business, and that's wonderful. 



but there isn't a lot of profit in it. The 
T.V. market is not growing very much; it 
is primarily a replacement market." 

One area into which Johnson thinks 
Heath can expand, capitalizing on its 
expertise in electronic education, is teach- 
ing service technicians to repair and 
maintain high technology equipment: "A 
lot of service organizations have been 
servicing mechanical gasoline pumps, for 
example, for years. Now they have to 
learn how to service digital ones. We're 
in a position to teach them how— we know 
how to teach people to do things step-by- 
step." 

He believes Heath will continue to offer 
high technology items in kit form. Research 
the company has done reveals that the 
desire to have something innovative and 
the desire to have a hand in creating it 
are very influential in Heath customers' 
decisions to buy. 

In addition. Johnson promises that Heath 
will not abandon quality. "This decision 
has forced us into a position of occasionally 
having a product that costs as much or 
more than the mass-produced, assembled 
version." he says. 

"It boils down to this: if a product requires 
a great deal of labor and there is a relatively 
small market for it and the industry is not 
making 10.000 a day. we can save the 
customer a lot of money. But when the 
industry tools up and starts making products 
at the rate of 10,000 or 100.000 a day. 
they take all the labor out— their economies 
or scale are so much greater than ours 
that by the time we write the manual and 
pack up all the parts, our labor can cost 
us as much as running a Zenith T.V. set 
down the assembly line. 

"In consumer products, when the 
industry is tooled up, we get out. We got 
out of the calculator business, and we did 
the same when we had the first CB 
unit— we can't be competitive when the 
market gets flooded. 

"Our thing is technology. We didn't 
invent the microprocessor, but when chips 
are expensive, before they slide down the 
price curve, we sell direct. We don't have 
any of the labor— the customer supplies 
that. We can get it into a consumer 
application quickly. We have digital marine 
gear, digital television sets, digital audio 
gear, and probably as many micro- 
processor-based consumer products today 
as anybody. 

"But as the industry tools up to make 
them by the bunches, we will go on to 
something else. Proof of this is the fact 
that 47% of the products that were in our 
catalog in 1978 are gone, and half the 
dollar volume that we expect from the 
current catalog will be from products that 
are less than three years old. We have to 
keep coming up with new ideas, new 
things." rj 



96 



CREATIVE COMPUTING 



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' 




Bruno B. Wolff, Jr. 



Simulation means making something act 
like the real world. There we have cause 
and effect, strong and weak influences, 
thresholds and limits, chance events, 
cooperation and competitive situations— all 
factors in an outcome or result. 

In writing computer programs there are 
several programming techniques that are 
useful in simulating a certain event. 
Although I will describe these techniques 
using Apple Integer Basic and Applesoft, 
these techniques are easily transferable 
to other forms of Basic and to other 
languages as well. 

This article will deal with cause and 
effects, giving some hints on how to get 
outputs that relate to certain inputs. We 
will present some ideas on additive and 
subtractive influences; weighted influences; 
thresholds and limits: straight line (linear). 
curved (curvilinear), logarithmic, and 
trigonometric relations. 

Then we will discuss chance events, 
going into uniform, normal, skewed, and 
absolute distributions. Don't leave yet: it 
isn't as complicatd as it sounds. 

Then we'll go into some ideas on 
cooperative and competitive techniques. 
The philosopher David Hume believed 
there was no such thing as cause and 
effect — that there was just a succession 
of events to which we ascribed a cause 
and effect relationship if the one followed 
the other often enough. 

Well assume, though, that one thing 
can cause another. Let's try a simple idea. 
We have a bushel of seed corn containing 
12.000 seeds. Each seed can produce 15 
ears of corn. If we plant all the seed (our 
cause) we'll get a certain effect — lots of 
ears of corn. 

EARS = SEEDS* 15 

Bruno B. Wolff. Jr.. 2004 E. Kensington. Shore- 
wood. W I 53211. 

AUGUST 1981 



This is a very simple simulation. But we 
know we need rain, a proper growing 
season, fertile seeds, the right fertilizer, 
pesticides, and proper acreage to grow 
crops. What is the cause of the corn that 
grows? Actually all of these factors influ- 
ence the growth of the corn. Some 
influence the growth more than others, 
and some act only within certain limits, 
or even act adversely outside certain para- 
meters. 

So we can have too little or too much 
rain, not enough or too much fertilizer, 
or we can apply pesticides up to a certain 
amount beyond which they no longer have 
an effect. 

Let's take these different situations one 
at a time. First, let's see how we can 
weigh the influence of one event upon 
another. It may seem obvious, but some 
influences are positive and others negative. 
So. for instance, if the insect population 



grows, it has a negative effect on our 
corn production. 

We can present a series of general 
formulae. "Y" will represent the effect 
and "X" the cause. 



No. 



Formula 



Net Effect 



1 Y = A + B '(X+C) positive 

2 Y = A-B*(X+C) negative 

3 Y = A + B /(X+C) negative 

4 Y = A-B/(X+C) positive 

In these formulae A. B. and C are 
constants, each of which affects the 
influence of the cause. Did you notice 
that 1 and 2 are really the same if we can 
let constant B have a negative value? The 
same holds true for 3 and 4 although here 
the minus sign in front of B is really positive 
in the influence of X on Y. By a positive 
influence I mean that as cause X gets 
larger, effect Y gets larger. 



i Lilting l.i 



50 TEXT 
100 INPUT "ENTER THE NUMBER OF VALUES OF X YOU WANT TO RUN ";K 
110 DIM Y(K) 

120 FOR J-l to K:Y(J)-0:NEX1 J 

130 INPUT "ENTER THE MAXIMUM VERTICAL VALUE":HV 
140 INPUT "tNIrR THE MINIMUM VERTICAL VALUE":LV 
150 IH-279/K 
160 CV»191/ABS(HV-LV) 
170 REM INSERT BETWEEN LINES 200-499 YOUR EQUATION USE X FOR THE 

INDEPENDENT VARIABLE (THE CAUSE) AND Y FOR THE DEPENDENT VARIABLE 
(THE EFFECT) 
180 REM CONSIDER X ANY Y AS ARRAYS DIMESNIONED TO THE MAXIMUM NUMBER OF 

TRIALS 

190 HCR2 

195 OOLOR-2 

500 FOR J - 1 TO K 

510 XP-1HMJ-1) 

520 YP-191-CV*(Y(J)-LV) 

530 FOR L - 191 TO YP STEP - 1 

540 HPLOT XP.L TO XP-UH.L 

550 NEXT L 

560 NEXT J 

570 END 

99 



Strategies, continued... 

Run this little test program to see how 
this works: 

100 FOR X = 1 TO 10 
1 10 FOR B = -5 TO 5 
120Y = 100 + B*(X + 1) 
130 PRINT Y:" : 
140 NEXT B 
150 PRINT 
160 NEXT X 
170 END 

You can see how the constant B affects 
the relationship. 

In order to make this presentation more 
meaningful, you may want to graph out 
the various formulae. Listing 1 is an easy 
to input and use generalized graph program. 
You can use this, as you read this article, 
to illustrate the effect of various changes 
in variables or to graph out changes later, 
as you use some of the techniques in 
writing your own simulations. 

Notice that the test program, if you use 
the graph, plots in a straight line. This 
kind of relationship is called linear, i.e.. 
for each unit increase of X. there is a 
constant increase (decrease) in Y. 

Let's give some names to "A." "B." and 
"C" that describe their influence on the 
result. "A" is a starting point. It can also 
be a minimum or maximum. If it is very 
large in relation to X, it can affect the 
magnitude of the effect of X on the 



formula. Let's call this the size factor. "B" 
is what tells how big a jump we make 
each time X changes. It affects the scale 
of X. We call this the scale factor. 

"C" regulates how much the scale moves 
when X changes. If "C" is large, sensitivity 
is low. If it is small then Y becomes more 
sensitive to X. "C" is. then, the sensitivity 
factor. 

All three factors work together, of 
course, but our names give you a feel for 
the principal influence of each. 

Let's go back to our cornfield again. 



Always be sure to set 

limits for values that 

in reality cannot go 

below or exceed a 

certain value. 



and just consider the effect of fertilizer. 
Even if we put no fertilizer on. we'll grow 
corn. Let's also now combine our seeds 
parameter to see how two influences can 
affect the result. 

Where F=bags of fertilizer, S=bushels 
of seeds, and H=harvest in bushels, let's 



print out the effect of changing both factors. 
If you want, use the generalized graph 
program to plot this. 

100 FOR S= 10 TO 15 
120FORF = 5TO10 
130H = S*(10+F/10) 
140 PRINT H 
150 NEXT F 
160 NEXT S 
170 END 

Now let's take a look at thresholds and 
limits. In our case we can say that rain 
falls within certain limits. It can never be 
less than zero and its upper limit is restricted 
by some historical maximum. 
100IFRO.THENR =0 
105 IF R > 20 THEN R = 20 
110H= 15-15AR + 1) 
As R (for Rain in inches) increases, so 
does H (the harvest). If R=0, what is the 
value of H? We could say that the threshold 
value of R is 1. What if we change the 
formula slightly. 

110H= 15-30/(R + l) 
Now R must be greater than 1 for H to 
be positive. You'll notice I sneaked in 
lines 100 and 105 above. This is one way 
to set a limit so you don't go below zero 
where that's an impossibility. I'd caution 
you to keep this little warning in mind: 
always be sure to set limits for values that 
in reality cannot go below or exceed a 



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Strategies, continued. 

certain value. In the second formula wr 
lower limit should be set for R? 

Try this in your machine. 

100 FOR R = 1 TO 15 

110H=15-30/(R+l 

120 PRINT H 

130 NEXT R 

140 END 

Here's another way to set a limit using 
a combination formula. We assume that 
adding pesticides is a way to increase the 
growth of our corn. But again, as in the 
rain, we need a minimum amount, but we 
also recognize that as we add pesticide 
we begin to flatten out its effect, and 
more and more of the pesticide goes to 
waste. 



H = 15 + 



P*10-8 
P+ 1 



Write a Basic program to illustrate the 
effects of the pesticides, and see what 
happens. 

This last example brings in another point, 
leading into our discussion of curvilinear 
equations. 

If you tried to graph the last equation, 
your plots no longer traced a straight 
line. The amount of increase in Y with 
respect to an increase in X was no longer 
uniform. 

Here are examples of some curves that 
plot in various forms of curves. 



Y= 2- 

X 


hyperbolic 


Y= log X 


logarithmic 


Y= x' 


parabolic 


Y= nAX 


exponential 



Y= SORIRA2-XA2I circular 



Y= sin X 



sine curve 



The hyperbola is a good curve for an 
event which, most of the time, has little 
effect, but once in a while has a very 
large effect. In our example a plague of 
locusts or other insects could l>e set to 
occur as a function of time the seven 
year locust— or on a random basis. We'll 
talk about random numbers a little later. 

h= J52 

(YMOD7) +1 
Y h 

1980 14 

1981 100 

1982 50 

1983 33 

1984 25 

1985 20 

1986 16 

Logarithmic and exponential curves are 
useful for showing growth curves of self- 
reproducing populations. 



Circles, sine curves or other recurring 
kinds of curves are good for adjusting to 
seavmal events. In our formula the growing 
season could be set to a sine curve. 

100 FOR X = TO 3.14 STEP .05 

I10H = SINX + H 

130 NEXT X 

If you want to watch this on your 
machine add the following lines as a 
delay: 

115 FOR J = 1 TO 500 

120 NEXT J 

125 PRINT H 



If we had the ability to 

measure all the causes 

of an event, we could 

compute or infer what 

would happen. 



iLisiini! 3.1 



This accumulates the harvest over a 
period of time starting out slowly, reaching 
a faster growth at the height of the 30-day 
harvesting season, and tapering off at the 
end. 

Let's now undertake a synthesis, a putting 
together, of several of the independent 
formulae and make them interact, augment, 
or decrement each other to produce a 
simulation. 

Let's first review the several formulae 
already considered. 

H=S*15 

H=S»(10+F/10) 

H = 15-30/(R+l) 

H=15+(P*10-8)/(P+l) 

H=100/«Y MOD 7)+l) 

H=SUM OF SINX FROM TO 3.14 

Now let's write an Applesoft program 
to bring this all together. See Listing 2. 



1 1 istimi 2.1 



90 S-S/2000 

100 FOR J-0 TO D STEP .01 

110 H«(S*(15»F/10)-S*20/(S*l)/3 

120 H-H«(P*H*.7-H/3)/<P»l) 

130 TH-TH»H*S1N(J) 

U0 NEXT J 

150 MD=INT((Y/7-INT(Y/7))*7«.05) 

160 TH-TH-TH/(MD*l)/2 

165 IF TH THEN TH-0 

166 TH-INT(TH) 

167 HOME 

170 PRINT "YOUR YIELD WAS " ; 
HI;" BUSHELS" 

Notice that we have changed some of 
the constants, scale factors, and sensitivity 
factors to weight various parts of the 
formula more heavily than others. We 
also had to create a MOD function in line 
150 because Applesoft, unlike Integer. 
does not have this function as part of the 
interpreter. 

Now let's put in a way for you to set the 
variables. See Listing 3. 



10 



20 
22 
25 
30 

32 
40 

42 
50 

52 
54 



PRINT "ENTER LENGTH OF 

SEASON IN DAYS " 

INPUT " NUMBER FROM 1 TO 90 ";D 

IF D<1 OR D>90 THEN 20 

D-D*3. 14/90 

INPUT "ENTER AMOUNT OF SEED, 

0000 "; S 
IF S<0 or S>50000 THEN 30 
INPUT "ENTER TONS OF FERTI1UER, 
FROM TO 100 "; F 
IF F<0 or F>100 THEN 40 
INPUT "RAINFALL IN INCHES, 
FROM to 20 "; R 
IF R<0 OR R>20 THEN 50 
IF R>15 THEN R - 30-R 

We should halt here to note that we are 
trapping all input size errors and that in 
line 54 we are adjusting the rainfall to 
allow for too much rain. 

60 INPUT "ENTER TONS OF PESTICIDE, 

FROM TO 50 ";P 
62 IF P<0 OR P>50 THEN 60 

70 INPUT "ENTER THE YEAR ";Y 

72 IF Y<1 THEN 70 

Now take a few minutes sometime to 
try out this program varying the several 
parameters and see what kind of farmer 
you are. 

To make the program more interesting 
you might assign cost figures to the seeds, 
fertilizer, and pesticide and determine a 
strategy for spending a predetermined 
amount of funds. To do that. add the lines 
in Figure I to the program in Listing 3. 



5 


PRINT "YOU HAVE $10,000 TO SPEND. 




SEED IS $.10 PER SEED; FERTILIZER 




$500 PER TON; AND PESTICIDE 




300 PER TON." 


6 


DO- 10000 


34 


Dl"DO-S*.l 


36 


IF Dl>-0 THEN 39 


37 


COSUB 200 


38 


CO TO 30 


39 


DO-Dl 


44 


Dl-D0-F*500 


46 


IF Dl>-0 THEN 49 


47 


COSUB 200 


48 


CO TO 40 


49 


DO-Dl 


64 


Dl-D0-P*300 


66 


IF D1>«0 THEN 69 


67 


COSUB 200 


68 


CO TO 60 


69 


DO-Dl 


175 


PRINT 


180 


PRINT "WITH GRAIN SELLING AT 




$12 A BUSHEL" 


185 


PRINT 


190 


PRINT "YOUR NET GAIN WAS" 


195 


PRINT" ";TH*12-10000»DO 


196 


PK1NT:PRINT 


197 


GOTO 6 


200 


PRINT "Y0l'"RE OVERDRAWN BY $"; 




ABS( DO-Dl ) 


210 


RETURN 



Now before all you real farmers tell me 
I know about as much about farming as 
certain kinds of your livestock do. let me 
say this example is purely fictitious. To 
simulate the real world you must gather 
data, put them all together and try your 
formula with many examples, fine tuning 
by changing constants (size factor), scale, 
sensitivity, weights, types of curves and 
so on. This is the creative part of simulation. 



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Strategies, continued... 

trying to understand what is going on in 
reality and converting that reality into a 
formula. 

In life many events occur seemingly by 
chance. If we can believe Leibnitz, nothing 
would happen by chance: we could, if we 
had the ability to measure all the causes 
of an event, compute or infer what would 
happen. We could predict the future with 
certainty. But, of course, we can't even 
begin to get all the measurements we 
need to predict an event. 

Look at weather forecasting or sports 
handicapping. The best we can do is 
compute the probability of an event— that 
is, that it has such-and-such a percent 
chance of occurring. We can get all the 
data we can to increase our knowledge 
about the causes of the event to improve 
the accuracy of our prediction. So in 
weather forecasting we read pressure, get 
reports from other stations, look at his- 
torical data, and so on. In sports, we 
review past performances, look at the 
injured lists, see what the teams" home 
and road records are. Some prognosticators 
read biorhythms or consult astrological 
tables. 

In simulation we duplicate these tech- 
niques by assigning a percentage value to 
each outcome. The theory of probability 
had its origin in the computation of 
gambling situations. Cards, dice, roulette, 
and such games of "chance" all. in a sense, 
model life in that certain events occur 
randomly, but with a certain degree of 
probability which can be computed rather 
accurately. So we throw a die and we can 
say there's one chance in six that a "four" 
will turn up. Fortunately, in computing 
we don't have to throw dice, pick a card, 
or spin a wheel to simulate a random 
event. We have that wonder of wonders, 
the random number generator. 

Typically these generate a number > =0 
and < 1.0. These numbers are uniformly 
distributed, i.e.. there is an equal chance 
of generating .02 as .03; or > =.02<.03 
as > =.05<.06. Just as we can generate 
different kinds of curves with equations 
we can make a random number operate 
in a nonuniform way by putting it into a 
formula that will generate a dependent 
random number that is distributed as we 
want it. 

Here are a few examples in Applesoft 
formula notation. 
Formula 1 

100Y=XA(RND(1)»10) 
1 10 END 



Formula 2 

100FORJ=1TO 10 
110Y=Y+RND(1)«2 
120 NEXT J 
130Y=Y/10 
140 END 



Formula 3 

100Y=RND(1)A2 

1 10 END 
You can use any of the other formulae, 
as well, to generate the kind of distribution 
you want — logarithmic, hyperbolic, 
parabolic, and so on. 

One of the more useful formulae that 
we can use to represent reality is Formula 
2 above. As you may know, certain events 
occur in what is called a normal distribu- 
tion—the well-known bell-shaped curve; 
seemingly random events like people's 



Seemingly random 

events like people's 

height, annual rainfall, 

scores of tests, 

imperfections in 

manufactured products, 

and so on, occur in 

normal distributions. 



height, annual rainfall, scores of tests, 
imperfections in manufactured products, 
an so on, occur in normal distributions. 
So. if you want to approximate these kinds 
of events, like the rainfall in our example, 
we can use a formula that will approximate 
a normal curve. 
300FORN=1TOK 
310R=R+INT(RND(1)»2) 
320 NEXT N 
330E=INT(R*F) 

This is a general formula you can use 
to generate a pseudo normally distributed 
number. 

E is the value returned to your program. 
The average value is equal to K*F/2. So, 
in the example above if we want our rainfall 
on the average to be 10 inches, we could 
useK=20andF=l or K =40 and F=0.5, 
etc. 

Sometimes we don't want to have a 
perfectly normal curve, but we want it to 
tail out more to one side than the other. 
These are called skewed distributions; a 
simple way to do this is to change the 
program slightly: 
305 RT=INT«RND(1)*2) 
307 MD=INT((J/3-INT(J/3))*3+.05) 
310 IF RT= 1 AND MD= 1 THEN 305 
315R=R+RT 

Then follow with lines 300-330 above. 
Try both of these formulae 15 or 20 
times and see how they plot. You can use 
the generalized graph program by adding 
the following lines: 
200 TEXT 
210 INPUT "INPUT CURVE 

SMOOTHNESS FACTOR";M 

104 



220 INPUT-INPUT MEAN 
CONSTANT";F 

230 FOR L=l TOM 

240 R=0 

340Y(E)=Y(E)+1 

350 NEXT L 

360HGR2 

See what the curves look like varying 
M. K and F. The larger M, the smoother 
your curve. K is the largest value of Y 
and K*F/2 is the mean. 

Listing 4 is another, more complex 
program that's an even better normal 
random number generator. Your main 
program, of course, would have line 100 
set in some hard coded way and call the 
normal random routine as a subroutine; 
but we'll put it in as an independent 
program. Once again it would be fun to 
graph this for the returned value. In this 
program though, we work backwards. "X" 
becomes the dependent variable and "Y" 
is the independent variable which is the 
value returned to your program as the 
normalized random number. Let me explain 
the values "M" and "S." "M" is the average 
value you expect to get over a number of 
trials. "S" is what is known as the "standard 
deviation." Two thirds of the values put 
out by the program will be within + or - S 
of the mean. Ninety-five percent will be 
within 2*S and - 2*S of the mean, and 99 
percent within 3*S. 



iLislini: 4.1 



100 INPUT "MEAN AND SD ";M,SD 

110 T-O 

120 R-RNO(l) 

130 FOR Y-M-4*SD TO M«4*SD STEP .5 

140 X-.399*(2.7183A<-5.*<<Y-W)/SD)A2)) 

150 T-T*> 

160 IF T/2/SD>R THEN 180 

170 NEXT Y 

180 PRINT "NORMALIZED RANDOM NUMBER- " 

190 END 



You can use this to generate rainfall in 
your corn program; a mean of 10 with a 
standard deviation of 5 would work 
nicely. 

The last random distribution III discuss 
I call the absolute. Absolute values can 
be generated in two ways— directly and 
by array. What do we mean by absolute? 
We mean there is no equation to link the 
cause and the effect. We get the effect by 
the cause pointing to a specified result. 

Here's one using the direct method in 
Integer Basic. 

100Y=20 

1 10 IF RND( 10)> 3 THEN Y= 10 

This method can also be used to branch 
which, while not as direct a cause-effect 
relationship, still leads to the program 
doing certain things in a random way. I 
use this in conjunction with other variables 
in a baseball game to determine to which 
field a ball is hit. If a batter is right- 
handed, the variable BLR is set to 15, if 
left-handed. Remembering that left-field 

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Strategies, continue 

is 7. center 8, and right 9 and that lefties 
hit more often to right and vice versa, we 
use the following formula to show what 
field the ball goes to on a fly (using Integer 
Basic): 

FIELD =(75- BLR+RNDl 25)1/10 

For a righthander the first part of the 
equation gives a value from 70 to 94 and 
for a lefty from 75 to 99. Therefore, a 
righthander will go to left on value of 70- 
79(10). center from 80-89(10) and right 
(90-94M5), i.e.. 40%. 40%. 20%. And the 
reverse for a left-hander. 

The second absolute method is to fill 
an array with values and address a cell in 
the array by linking the random number 
to the position in the array. Here's an 
example in Integer Basic. 

Y=X(RND(20)+1) 

This will put the value of one of the 20 
values in the X array into Y. In a football 
game I've used this to call up the average 
gain for a certain play. This is useful for 
situations calling for certain specific 
characteristics where the value of X is 
more a name or pointer than a causal 
force. You might use it to identify the 
characteristics of a randomly selected 
monster in an Adventure type of game. 

Competitive Strategies 

We've talked enough about random 
counts. Now we want to present a few 
ideas on competitive (or cooperative) two 
or more player situations where the choice 
of one player affects the results of another 
or where the combined effort of both 
either affects each other's results or a 
third effect. 

As with the random number influence, 
we can divide our competitive strategies 
into two classes— direct and array. Here's 
an example of the direct using an example 
from the baseball game mentioned above. 
We need to set up a mechanism to account 
for the fact that left-handed batters hit 
better against right handed pitchers, and 
that switch hitters hit about equally well 
against either. From an array for pitchers 
we read PV(N) the variable being set to 
15 if right-handed and if left-handed. 
The value BV is also read from the batter's 
array and is set R=15. L=0. and switch- 
hitter 7. The larger the value of V. the 
better it is for the hitter. 

V=ABS(BV-PV)*5-35 

Another simple trick is to set a value 
and then change it if the two players 
match or don't match on a choice. For 
instance, following through on the baseball 
image, if the batter guesses correctly on a 
pitch he gains an advantage. 

100 V=-50 

1 10 IF PITCH = GUESS THEN V = 

Now we have two parts of the competi- 
tive result which we can put into one 
formula: 

V=ABS(BV-PV •5-85+50* (PITCH= 

GUESS I 



Another way to compare the actions of 
the two players is to compute a mean of 
the two inputs and affect the formula by 
comparing the differences in this mean. 

I have a manufacturing game in which 
a final product price must be set indepen- 
dently by each of the "companies." So we 
have for three companies: 

AVE=(P(l)+P(2) + P(3))/3 
S(N)=1000*AVE/P(N) 

This relates S(N). the market share of 
Company N to the average price. 



When we set up a 

formula, obviously we 

have some value in 

mind as regards what 

the effect of the various 

causes should be. 

We can insert a factor to make the 
equation more sensitive to price. 

SIN) = 5000*(AVE/P(NH).8) 

This formula eliminates any market for 
a company that charges 20% above the 
average price. You can vary the sensitivity 
to price by making the sensitivity constant 
(remember that label?) anything from 
-0.99 to any plus value. At plus values the 
market would begin to become very 
insensitive to price. If you change the 
sensitivity constant you must also adjust 
the scale constant to keep your expected 
result in balance. 

Now say we want to introduce marketing 
expense as an option of the Company. 
We can assume that the more a company 
spends on marketing the larger the market 
it can engender, but it must also compete 
with the marketing of opposing 
companies. 

T = M(1) + M(2) + M<3) 

S(N)=M(1)/T*1000 

Here we determine the market share 
by a straight percentage of the market as 
reflected by marketing expenditures. But 
we may want to recognize that marketing 
for such and such a product is more or 
less sensitive to marketing expense. So 
we can add a factor to account for this. 

S(N) = (5000+M(l))/T*700 

The quality of a product is also a factor 
and we can relate quality to quality control 
and research and development. Once again 
we could make this a straight reflection 
of the effect of these expenditures. Or we 
can immediately recognize a size factor 
to diminish this effect. 

TQ=Q(1)+Q(2)+Q(3> 

S(N)=1000»(3+Q(N)/TQ) 

Finally, let's look at the array as a 
competitive or cooperative factor. We'll 



leave our management game for a while 
and go back to sports. The offensive team 
in football flashes in a play from the bench 
and the defensive captain also gets the 
word on how he should line up his team. 
This lends itself to picking two members 
that define a cell in a two-dimensional 
array. We use this in a football game to 
pick absolute numbers to adjust other 
parts of the formula to compute the result 
of a play. If the offense picks a running 
play up the middle and the defense has 
loaded for such a running play, we will 
send a minus factor to the formula. If the 
defense was looking for a run and we 
pass, then a plus factor is transmitted. 

We can represent this in Applesoft Basic 
as: 

R=C(O.D) 
Where O=offensive play and D=defensive 
play. 

Expected Results 

Before we conclude this article. I want 
to spend a title time on expected results. 
When we set up a formula, obviously we 
have some value in mind as regards what 
the effect of the various causes should 
be. We'll produce so many bushels of 
corn, or get a base hit so often, sell so 
many widgets, or gain so many yards. 

For the simple formulae we have used 
in this article, we can easily compute the 
average or expected result of an equation. 
If we have an equation such as Y = X+C 
where values of X are between L (low) 
and H I high I. we can compute the average 
results by the following formula: 

AVE Y=«HA2)/2+C , H)-«LA2)/2+ 
C*L)/(H-L) 

For a number produced by a random 
variable of to 1. a similar formula will 
work. 

Y=10*RND(X)+5 



AVEY 



10*i 1 >+ 1*5=10 



The low value, being 0, drops out of 
the equation. An easy way to do this is to 
put your random number to .05 and you'll 
get your average result in a linear 
equation. 

Another way to get a mean value is the 
brute force method. Just run the program 
many times, accumulate the results and 
divide by the number of trials, and you'll 
have a very close approximation of the 
expected value. 

For nonlinear equations, the formulae 
get a little more complicated. 1 recommend 
you use the brute force method then or 
dig out your calculus book and review 
definite integrals. 

We've only touched the surface of a 
highly complex field. I hope you've gotten 
a few new ideas on a very practical level 
to help you in your attempts to convert 
reality into equations so that the world is 
right there inside your monitor. □ 



AUGUST 1981 



107 



The National TRS-80 Computer Show 



Private Audiences 

with 
Top Programmers 




George Blank 



For the tiny handful of the general public 
who attended, the TRS-80 computer show 
at the Statler Hotel in New York in late 
May offered plenty of opportunity to talk 
to the best known programmers for the 
Radio Shack computers. The show was 
dominated by software suppliers, and the 
exhibitors, many of whom were program- 
mer-entrepreneurs, usually outnumbered 
attendees. Taking advantage of the free 
time and lack of attendance, many of the 
exhibitors renewed social contacts and 
made wry jokes about making enough 
money to cover their parking. 

The show was cosponsored by 80 Micro- 
computing published by Wayne Green 
who, despite his success in publishing 
magazines, has not been able to replicate 
it on the show circuit. Apparently he 
believes his magnetic personality will attract 
huge crowds, but it just hasn't worked. 
His previous show, in Boston two years 
ago, was also a disaster at the box office. 

Actually, the show displayed a vitality 
in the TRS-80 marketplace, with several 
innovative software products. Scott Adams 
of Adventure International had several 
new products, including one of the most 
complex space games yet marketed. Star- 
fighter, clearly an imitation of Atari's Star 
Raiders, comes with a 32-page instruction 
manual and it takes several hours just to 
figure out how the display and commands 
work. Another product introduced by AI 



was Commbat, a war game to be played 
by two persons on separate TRS-80 Model 
I computers connected over modems. 

Bill Hogue of Big Five Software, supplier 
of some of the most popular TRS-80 arcade 



Many of the exhibitors 

renewed social contacts 

and made wry jokes 

about making enough 

money to cover 

their parking! 



games, displayed new packaging and an 
innovative disk format that allows the same 
diskette to be loaded in either a Model I 
or Model III computer. 

Roy Niederhoffer, teen-age president 
of Software Innovations, was there with 
Name That Tune, a computer imitation 
of a television quiz game, complete with 
commercials for his other software 
products. 

Quality Software Distributors introduced 
the latest entry in the Scripsit program 
modification sweepstakes, Scriplus. The 
most innovative feature is an alphabetized 



diskette directory callable from within 
Scripsit. Another product handled by QSD 
is Omnitech's Move 3-2-1 and Move 1-2-3, 
a pair of programs that move some files 
back and forth between Model I and Model 
III computers. The programs come in a 
single package, but you need Percom's 
Doubler double density disk controller 
and Double DOS to down load programs 
from the Model III to the Model I, and 
the program cannot handle long files with 
extended directory entries. 

Hardware products demonstrated at the 
show included two speech synthesis units. 
The Micro Mouth, by Micromint, sells 
for $199 and has a fixed 255 word voca- 
bulary and remarkably clear and under- 
standable speech. Type-'N -Talk, by Vodex 
is far more ambitious. It contains a text 
processor that takes ordinary text and 
processes it into speech. The unit, selling 
for $349, contains a microprocessor and 
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standard RS-232 port. While the speech is 
not as good as that of the Micro Mouth, 
the unit is flexible and about as easy to 
use as a printer. Any text is interpreted, 
but you might have to tamper with spelling 
to get it to sound right. Our name becomes 
CRE ATIV COM PEWTINGG and it is 
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will be offering several programs to support 
the Type-N-Talk on popular com- 
puters, rj 



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How to Solve It- With the Computer 



PART 8 



Donald T. Piele 



"Learning about computers without learning how to program 
is like learning about cars and not learning how to drive. " 

—A Student 



It is common today to find people in all walks of life who 
have a deep disdain for computers. At all grade levels in 
education, there are those who are openly anti-computer and 
are proud of it. Some teachers firmly believe that computers 
in the classroom will diminish the ability of students to think 
for themselves and will lead to their ultimate dependence on 
a machine. 

Fortunately there is evidence of a changing attitude among 
many educators towards computers in the classroom. A 
recent study funded by the National Science Foundation has 
shown that there is strong support among elementary and 
secondary teachers, parents, and administrators for the 
development of computer literacy for all students. The 
PRISM study (Priorities in School Mathematics) 1 1 1. carried 
out by the National Council of Teachers of Mathematics, has 
made important recommendations which relate to the use of 
computers in the classroom. These recommendations reflect 
the priorities of teachers, parents, and administrators at the 
local school level. 

The objective of the PRISM study was to provide guide- 
lines and suggestions for curriculum changes in mathematics 
for the lWO's. Two of the nine major areas under investiga- 
tion were problem solving and computer literacy. 

Problem Solving 

The one area which all respondents agreed should be 
emphasized in the 1980's mathematics curriculum was prob- 
lem solving. Over 95% identified the goal of problem solving 
as the development of methods of thinking and logical rea- 
soning. Top priority was given to the development of new 
materials beginning at the elementary school level. 

The problem with teaching problem solving is that it is not 
a traditional subject which can be mastered in complete 
detail. This understandably makes it difficult to teach prob- 
lem solving using the methods that have proven successful for 
more traditional subjects, such as fractions. However many 
texts try to do just this. The typical "story problem," so often 
used in text books ostensibly to develop problem solving 
skills, usually turns out to be an exercise in recalling a numer- 
ical fact or in fitting the problem into a memorized pattern - 
hardly a genuine problem solving experience. 



Donald T. Piele. The University of Wisconsin- Parkside, Kenosha. Wl 
33141. 



110 



Computer Programming and Problem Solving 

The bond between computers and problem solving is well 
established. Few people would deny the value of the compu- 
ter for solving problems. In fact the history of computers 
parallels the history of man's search for ways to automate the 
problem solving process. But computers do not solve prob- 
lems by themselves. They need instructions from humans. 
Computer programming -the creative art of transforming a 
set of humanly constructed procedures into machine execut- 
able code -is the crucial link between man and computer. 

New Problem Solving Strategies 

Computers are really simple-minded. High speed computa- 
tions are the thing they do best. But never underestimate the 
power of arithmetic if it can be done fast enough. Donald 
Greenspan, formerly of the University of Wisconsin and now 
with the University of Texas, has recently published a book 
which applies the computational power of the computer to 
the development of discrete counterparts to many classical 
physical phenomena |2|. Using only arithmetic he is able to 
establish exactly the same laws of conversation and symmetry 
that exist in classical continuum mechanics. The simplicity of 
his approach is extraordinary. 

Ideas which utilize the power of high speed arithmetic will 
become better understood by younger students as computer 
programming begins to find its way into the elementary and 
secondary curriculum. In fact many mathematical techniques 
that are classically quite complicated are extremely simple 
when approached with the computer. 

This month. I would like to focus on a set of examples that 
relate very closely to the kinds of problems that students are 
asked to solve in mathematics courses. My objective is to 
contrast traditional techniques for solving mathematical 
problems with the way in which one might solve the same 
problem armed with a computer. I hope to show that problem 
solving with the computer has the potential for providing 
genuine problem solving experiences which are simple, prac- 
tical, and interesting. 

Lesson #8 (Beginning Students) 

The Setting: The proverbial "story problem" in mathema- 
tics is the bane of most students. After many tortuous experi- 
ences of trying to match up a problem with the method they 
have been provided with to solve it. students come away 
believing, at best, that problems are solved in only one way. 
and at worst failing even to understand the relationship 
between a solution and a problem. You have probably heard 
students argue that a wrong result must be right because. "I 
used the same formula you did: how could it be wrong!" 

What is woefully lacking for most students is the opportun- 
ity to see solutions for problems evolve through efforts of 

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rive It, continued. 



their own and to have the opportunity to experiment with 
relationships and patterns. This is where the computer can be 
a great help. For example, consider the following problem. 

The Problem: Pigs and Chickens. A boy and his sister 
visited a farm where they saw a pen filled with pigs and 
chickens. When they returned home, the boy reported that 
he saw 18 animals in all. and his sister remembered that she 
had counted a total of 50 legs. How many pigs are in the pen? 

The Discussion: This problem has an interesting effect on 
people. Far too many who try it fail because they try to 
remember an algebraic formula to plug into. Others success- 
fully set up the algebraic machinery to solve it but then fail to 
execute the symbol manipulations properly — usually because 
they have forgotten at least one crucial detail. In the alge- 
braic setting this problem can be solved by solving the set of 
simultaneous linear equations: 

4P+2C=50 

P+C=18 

On the average, young kids, who have never seen algebra 
before, do better with this problem than adults because they 
look at it with an open mind. 

Since this problem is presented here to illustrate more than 
just how to find an answer, we will convert this problem in a 
programming problem. This will also provide an opportunity 
to gain experience with the relationship between pigs, chick- 
ens, and legs which will eventually lead to insight into the 
problem. 

The Programming Problem: Write a program which will 
print out the number of pigs, chickens, and the total number 
of legs for all combinations of pigs and chickens that add up 
to 18 animals. 

The Algorithm: A FOR-NEXT loop can be used to com- 
pute the number of legs for each combination of pigs and 
chickens that add to 18. The number of chickens, of course, 
is 18 minus the number of pigs. 
Chickens =18-Pigs 
The total number of legs is clearly. 
Legs=4»Pigs+2»Chickens 

The program: 

10 PRINT "PIGS";TAB(15);"CHICKENS";TAB(32)- 
"LEGS" 

20FORPIGS=0TO18 

30CHICKENS=18-PIGS 

40 LEGS=4*PIGS+2*CHICKENS 

50 PRINT PIGS. CHICKENS. LEGS 

60 NEXT PIGS 

70 END 



RUN 






PIGS 


CHICKENS 


LEGS 





18 


36 


1 


17 


38 


2 


16 


40 


3 


15 


42 


4 


14 


44 


5 


13 


46 


6 


12 


48 


7 


11 


50 


8 


10 


52 


9 


9 


54 


10 


8 


56 


11 


7 


58 


12 


6 


60 


13 


5 


62 


14 


4 


64 


15 


3 


66 


16 


2 


68 


17 


1 


70 


18 





72 



Remarks: 

1. The program above is written in Applesoft Basic. In 
some forms of Basic the variables PIGS, CHICKENS, LEGS 
will need to be shortened to P.C.L. 

2. The table printout is separated into three fields by use of 
the comma in Applesoft Basic. Another Basic language may 
require the addition of the TAB function to line up the 
columns. 

3. The pattern that appears in this printout is very reveal- 
ing. Not only is the solution (7 pigs. 1 1 chickens) obvious but 
a pattern— an increase by two in the number of legs in each 
row— is also clear. In fact this observation can be used to find 
the solution quickly using only common sense: 

"If all the animals were chickens (the top row) then we 
would be short 14 legs (50-36). So we need to change chickens 
into pigs. Every time a chicken becomes a pig the number of 
legs increases by 2. We need 7 transformations to make up 
the 14 legs which means we need 7 pigs, leaving 1 1 chickens." 

To become a good problem solver, one must be aware of 
the patterns and relationships that exist in almost all prob- 
lems. Using the computer to display these relationships not 
only helps make the solution easier to find and understand, 
but also teaches students how to use a computer to gain 
insight into a problem. 

Additional Problems: 

1. Add more flexibility to the pigs and chickens problem by 
allowing the number of animals to be entered and not fixed at 
18. 

2. Another Problem: A carpenter agrees to work under the 
following conditions: He is to be paid $10 a day for his work 
for every day he works, but will be fined $12 for every day he 
misses. At the end of 30 days he has worked just enough days 
so as not to lose anything. Write a program which will print 
out the number of days worked, days absent, net pay. What is 
the solution? 

Lesson #8 (Intermediate Students) 

The Setting: The typical mathematics text does an honest 
job of trying to explain the origins of most algorithms before 
it highlights the essential part in bold type and assigns 25 
problems that use it. The teacher may also do a conscientious 
job explaining the development of the algorithm from funda- 
mental principles. But the student quickly learns that all you 
really have to know is how to plug the correct numbers into 
the right spots to get the assignment done. Why the algorithm 
works is lost in the mystery of algebraic magic. 

For example, consider the quadratic formula: The roots of 
the quadratic equation ax 2 + bx + c = can be expressed 
by the quadratic formula 

b± sjb* -4ac 
2a 
A typical application of this formula might be to find the 
values of x where the curve y = x 2 + x - 1 crosses the x axis 
(y - 0). By simply subs'tituting the coefficients into the quad- 
ratic formula we have: 

x = (-1 ± VE)/2. 

However, very little is learned about problem solving or 
about the meaning of the solution in the process. To most 
students the numbers that pop out of the quadratic formula 
are meaningless. It is merely a routine operation that must be 
performed in order to get the answers in the back of the 
book. 

But there is a strategy which can be implemented on the 
computer that is completely elementary and well within the 
ability of intermediate students to program. It is called bisec- 
tion. 

The bisection strategy can be explained by playing the 
game of Guess. The object of this game is to guess a mystery 

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number that lies between and 100 by asking questions that 
can be answered either yes or no. Using the bisection strategy 
one can reduce the possibilities for the mystery number in 
half by asking: "Is the number greater than 50?" If the answer 
is yes. then the number has been trapped in the interval 
(51, 100). If the answer is no. then the number is in the interval 
(0.50). The same strategy is repeated again on the reduced 
interval which contains the mystery number. In this way the 
size of the interval which contains the unknown number is 
cut in half at each stage until finally one possibility remains. 
This is illustrated as follows: 



Trial* 


Size of Interval 





100 


1 


50 


2 


25 


3 


13 


4 


7 


5 


4 


6 


2 


7 


1 



Including the final guess which names the mystery number, 
it requires at most eight questions to find the solution using 
the bisection technique. 

This technique is also the basis of a procedure that can be 
used to find the real roots of any smooth function F(X). We 
will use the quadratic function X 2 + X - 1 to illustrate this 
idea. First, consider a table of values for this function. 



-2 


1 



X + X-l 

1 
-1 

1 



This table tells us that the graph of the function is above the 
X axis at -2. below the X axis at 0. and above the X axis at 1. 
Since the quadratic function is a smooth graph and cannot 
make any sudden jumps in its graph, there must be a point in 
the interval (-2.0) where it crosses the X axis (i.e. X 2 + X - 1 
= 0). The same must be true for the interval (0.1) (see Figure 
1). The point at which this happens is called a root of the 
function and we can find it by using the bisection technique. 
The Problem: Write a computer program that will find the 
roots of the quadratic function X 2 + X - 1 by the method of 
bisection. Allow the user to input values for A and B and let 
the program test whether the interval (A.B) contains a root. 




roots 



The Discussion: The key to the bisection strategy is very 
simple. Suppose a smooth function F(X) has a different sign 
(+ or -) at two points X = A and X = B. For the sake of this 
discussion, assume that FlAOO and F(B)< 0. Then some- 
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region can be cut in half by picking the midpoint C = (A + 
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( 1 ) the region (A.B) is cut in half, and 

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maintained. 

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interval (A.B) decreases in size closing in on both sides on the 
root. It can be stopped whenever a desired degree of accur- 
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The Algorithm: Functions are defined in Basic by use of 
DEF FNF (X). For the quadratic function in question we 
have: 

DEFFNF(X) = X»X + X- 1 

We must test the function initially at A and B to make sure 
they have different signs. This is done with the SGN ( ) 
function: 

SGN(X) = lif X > 

SGN(X) = 0if X=0 

SGN(X)=-1 if X < 



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CIRCLE 102 ON READER SERVICE CARD 




Solve It, continued... 

Thus, to begin using the bisection mehtod we must have: 

SGN(FNF(A)) <. > SGN(FNF(B)). 

The SGN function is also used to check whether A or B is 
replaced with C = (A + B)/2. 

IF SGN(FNF(C)) = SGN(FNF(A)) THEN A=C ELSE 
B=C 

The absolute value function ABS(X) is used to test the size 
of the interval ( A,B). To be accurate to 5 decimal places in an 
absolute sense we use the test: 

IF (ABS(A-B) > .00001 THEN (continue bisecting) ELSE 
(print the approximate root C.) 

The Program: 

10 PRINT "BISECTION METHOD FOR FINDING ROOTS" 

20 DEF FNF(X)»X»X ♦ X - 1 

30 INPUT "ENTER A.B = ".A,B 

40 PRINT "TRIAL ROOT" . TAB (20) . "FUNCTION VALUE" 

50 E=. 00001 

60 IF SON<FNF(A))OSGN(FNF(B)) THEN 90 

70 PRINT "THE SIGNS ARE THE SAME, TRY AGAIN." 
80 GOTO 30 

90 C=<A+B)/2 

100 IF FNF<C)-0 THEN 140 

110 IF SGN(FNF(C))=SGN(FNF(A)) THEN A-C ELSE B=C 

120 PRINT C.TAB(20>,FNF(C) 

130 IF ABS<A-B)>E THEN 90 

140 PRINT "ROOT ■ ".C 

ISO END 



FOR FINDING ROOTS 

FUNCTION VALUE 
-.23 
.3125 
.013625 
-. 1210937 
-.0537109 
-.0192871 
-.0018921 
.0068512 
. 0024758 
.000291 
-.0008008 
-.0O0255 



BISECTION METHOD 
ENTER A.B * 0, 1 
TRIAL ROOT 

.5 

.75 

.625 

.5625 

.59375 

. 609375 

.6171875 

.62109375 

.61914065 

.6181641 

.6176758 

.61791995 

BISECTION METHOD FOR FINDING ROOTS 
ENTER A.B » -2.0 
ROOT » -1.6180345 



.000018 

-.0001185 

-.0000502 

-.0000161 

.000001 



.61804205 

.617981 

.61801155 

.6180268 

.61803445 

ROOT » .61803445 

Remarks: 

1. The roots computed by the quadratic formula are (-1 
±v/5)/2, which can be approximated by .618034 and 

- 1 618034. 

2. The quadratic formula is only good for finding roots of 
quadratic funtions while the bisection technique can be used 
with any function that can be expressed in a computer lan- 
guage. 

3. The absolute error of E = .00001 is fine for demonstra- 
tion purposes, but it is not satisfactory in general. If a root is 
very small, for example .0002, then testing for errors of .00001 
will yield an answer that is correct to only 2 significant places. 
To be sure of having an accuracy of at least 5 significant 
figures, use the relative error 

E = .000001 • (ABS(A) + ABS(B))/2. 
Additional Problems: 

1. Replace the quadratic function X*X + X - 1 with the 
sine function SIN(X). The sine function is zero at X - TC. Use 
the bisection program to obtain an approximation to TC by 
finding a root for the sine function between 2 and 4. 

2. The bisection program can also be used to find where 
functions intersect. For example, where does the curve Y - 
X intersect the curve Y = COS(X)? This happens, of course, 

AUGUST 1981 



n X = COS(X) or, expressed another way. when COS(X) 
- X = 0. Thus, finding the roots of the difference between the 
two curves is equivalent to finding where they meet. Find all 
points where these two functions meet. 

3. Finding the fifth root of 2 is equivalent to solving the 
problem X 5 = 2. This is equivalent to finding a roots of the 
function X*- 2 = 0. Use the bisection program to find s/T. 

Lesson #8 (Advanced Students) 

The Setting: A student working on a chemistry experiment 
recently has a question about a liquid dilution problem. A 
one-liter beaker of a concentrated solution was to be diluted 
with one liter of water. If the water had been added all at 
once, then the concentration of the liquid substance would 
be cut in half. But in this experiment the water was to be 
added very slowly, mixed completely with the concentrated 
liquid, and continuously discarded, so that only one liter was 
kept at all times. This can be seen by visualizing a full beaker 
(1) of a liquid solution which is being constantly diluted with 
water from beaker 0, instantly mixed, and the overflow dis- 
carded. 

























' 











1 












I 







Water 



Concentrated Solution 



What is the concentration of the liquid after it has been 
diluted in this fashion with one liter of water? 



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CIRCLE 161 ON READER SERVICE CARD 



117 




Solve It, continued. 

Without the computer, this problem involves setting up the 

proper differential equation.The student who asked about 

he problem had no idea how to set up such a problem much 

less how to solve .t. With a little knowledge of Basic and a 

solve PU,er problem is "^lively easy to understand and 

Problem I : Write a computer program which simulates the 
dilution of the liter of a concentrated solution with one liter 
of water. The dilution should be carried out gradually so that 
a small quantity of water is added to the liquid solution 
instantly mixed, and the same quantity of mixed solution 
discarded What is the final concentration of the diluted 
solution if the initial concentration is C? 

The Discussion: In the process of programming the compu- 
ter to solve this problem, we actually see what is happening at 
each stage in the dilution. In fact, if we can compute -The new 
concentration after the addition of a small quantity of water 
then we can easily find the final concentration by simplv 
repeating the process until all the water is added. Let M stand 
lor the number of milliliters of water that are mixed with the 
dilution. (One liter = 1000 milliliters.) If M is small, then the 
dilution process is nearly continuous. We begin with one liter 
of the solution with concentration C. After adding M millili- 
ters of water, the concentration is reduced to 

C/U + M/ 1000) I. 
Replace the old concentration with the new by setting 
C = C/(1 +M/1000). y~»mg 

This process of adding water, mixing the solution, and dis- 
3 an e ^ u "' ™>«uni of solution must be repeated 
1000/M times before the entire liter of water is used up The 
resulting concentration C is a good approximation to the 
solution for the continuous dilution program. 




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CIRCLE 1*3 ON READER SERVICE CARD 



The Program 



10 PRTNT "CONTINUOUS DILUTION PROBLEM" 

20 PRINT » »■■■■■■■■■■■■■■■■■■■■■■■■ 

30 INPUT "ENTER THE INITIAL CONCENTRATION >» •• , C 

22 1U N ^ T /^ ILLILITERS 0F WATER « DDED EACH STEP »> ",M 

t?, TIM?^ \ REM N = THE NUMBER OF STEPS 

60 D=M/1000 \ REM D = WATER IN LITERS 

70 T ^ REM T = MILLILITERS ADDED 

80 PRINT "MILLILITERS ADDED" . TAB( 20 ). "CONCENTRATION" 

90 FOR 1=1 TO N 

100 PRINT TAB(3).T,TAB(20).C 

110 C=C/<1+D) 

120 T=T+M 

NEXT I 
14o PRINT TAB(3>.T,TAB(10). "SOLUTION =" . TAB(20) ,C 

JTINIJOUS DILUTION PROBLEM 

ENTER THE INITIAL CONCENTRATION >» i 

II, I . L I', I . L {™ S 0F WATER ADDED EACH STEP >» too 

MILLILITERS ADDED CONCENTRATION 

1 

100 .90909091 

200 . 82644628 

300 .7513148 

400 .68301345 

"■"" .62092132 

61,1 ' . 56447393 

7 "" .51315812 

800 . 46650738 

'"'" .42409762 

1000 SOLUTION = .38554329 
MILLILITERS OF WATER ADDED EACH STEP >» 50 

MILLILITERS ADDED CONCENTRATION 

1000 SOLUTION = .37688949 

MILLILITERS OF WATER ADDED EACH STEP >» 10 
MILLILITERS ADDED CONCENTRATION 
1000 SOLUTION = .36971125 

MILLILITERS OF WATER ADDED EACH STEP »> 1 
MILLILITERS ADDED CONCENTRATION 
1000 SOLUTION = .36806335 

MILLILITERS OF WATER ADDED EACH STEP »> 5 
MILLILITERS ADDED CONCENTRATION 
1000 SOLUTION = .36797136 

Remarks 

1. The last four runs were made with the intermediate print 
out deleted. 

2. Notice how little the final concentration changes in the 
last three runs even though the number of steps has increased 
100 times. 

3. The limiting value of the concentration as M approaches 
zero would be the exact continuous solution. 

4. Those familiar with elementary differential equations 
will be able to understand the following argument which 
leads to an exact continuous solution: 

Let C(I) equal the concentration at step I. Then the rela- 
tionship we are using to express the new concentration from 
the old at each step can be written 

C(I) = C(M)/(1 +D). 
Using algebra we can rewrite this as 

C(I>-C(M) = -D»C<I). 
Let AC = C(I)-Cd-l). and A X = D. We can rewrite the 
expression again to read 



AC 
AX 



= -C. 



This difference equation leads to the differential equation 



dC 
dX 



= -C. 



118 



The solution of this equation is well known and given bv 
C = Co e * 7 

where C is the initial concentration. Substituting C= 1 and 

CREATIVE COMPUTING 




CIRCLE 141 ON READER SERVICE CARD 



^m 



Solve It, continued. 



X-l into this expression, we get the exact continuous solu- 
tion 

C = .36788. 

Problem 2: Expand Problem 1 to include a second concen- 
trated solution which is diluted with the discarded solution 
from the first concentrated solution. Write a program which 
will simulate the dilution of each substance and find the final 
concentration. The initial concentration and and the step size 
should be entered by the user. 




The Algorithm: Let CI and C2 be the concentration of the 
first and second solution respectively. If D is the number of 
liters added in each step, then the concentration of the first 
liquid is diluted at each step to give 

C1=C1/(1+D) 
as before. D liters of this solution is passed on the new 
concentrated solution and changes its concentration to 

C2=(C2+D»C1)/(1+D). 
The D*C 1 is the contribution from the previous beaker. 
The Program: 

10 PRINT "CONTINUOUS DILUTION PROBLEM 2 " 
20 PRINT ■—■—■■■■—■■—■ 

30 INPUT "THE INITIAL CONCENTRATION OF SOLUTION 1 »> " 
40 INPUT "THE INITIAL CONCENTRATION OF SOLUTION 2 >» " 
30 INPUT "MILLILITERS OF WATER ADDED EACH STEP »> ",M 
60 N-1000/M \ REM N ■ THE NUMBER OF STEPS 

70 D=M/1000 \ REM D = WATER IN LITERS 

80 T - \ REM T » MILLILITERS ADDED 

90 PRINT "MILLILITERS ADDED" .TAB < 20) , "SOLUTION 1". 

TAB (35), "SOLUTION 2" 
100 FOR 1-1 TO N 

110 PRINT TAB(3),T,TAB(20),C1.TAB(35).C2 
120 C1-C1/(1+D> 
130 C2-(C2+D»C1 )/(l*D) 
140 T-T+M 
150 NEXT I 
160 PRINT TAB<3),T,TAB(10>. "ANSWER 

TAB(33).C2 
170 END 

CONTINUOUS DILUTION PROBLEM 2 

THE INITIAL CONCENTRATION OF SOLUTION 1 >» 1 
THE INITIAL CONCENTRATION OF SOLUTION 2 »> 1 
MILLILITERS OF WATER ADDED EACH STEP >» 100 



.TAB(20),C1. 



MILLILITERS 


ADDED 


SOLUTION 1 
1 
.90909091 


SOLUTION 2 
1 
.99173555 


100 






200 






. 82644628 


. 97670927 


300 






.7513148 


.95621891 


400 






.68301345 


.93138209 


50O 






.62092132 


.90315838 


600 






. 56447393 


. 87236888 


700 






.51315812 


.83971335 


8O0 






. 46650738 


. 80578554 


9O0 






. 42409762 


.77108664 


1000 


ANSWER ■ 


. 38554329 


. 73603725 



MILLILITERS OF WATER ADDED EACH STEP >» 50 
MILLILITERS ADDED SOLUTION 1 SOLUTION 2 
1O0O ANSWER ■ .37688949 .73583189 

MILLILITERS OF WATER ADDED EACH STEP >» 10 
MILLILITERS ADDED SOLUTION 1 SOLUTION 2 
1000 ANSWER = .36971125 .73576197 

MILLILITERS OF WATER ADDED EACH STEP »> 1 
MILLILITERS ADDED SOLUTION 1 SOLUTION 2 
1000 ANSWER - .36806335 .73575889 

MILLILITERS OF WATER ADDED EACH STEP >» .5 
MILLILITERS ADDED SOLUTION 1 SOLUTION 2 
1000 ANSWER - .36797136 .73575901 



Remarks: 

1. The last four runs were made with the intermediate 
print out deleted. 

2. The limiting values for the concentrated solutions that 
result when M approaches zero would be the exact continu- 
ous solutions. 

3. Those familiar with differential equations will be able to 
understand the following argument which leads to an exact 
continuous solution. 

As shown in the remarks following Problem 1 , the concen- 
tration in the first solution satisfies the differential equation 



dCl 
dX 



— ■CI. 



The change in the concentration of the second can be de- 
rived by rewriting line 130 in the above program as 

C2(l) =JC2(I-1) + D»C1(I))/(I + D). 
Let AC2 - C2(I)-C2(I-1 ) represent the change in the concen- 
tration after each step in the dilution process. Let A X = D 
and write the last expression in terms of the difference equa- 
tion 



AC2 

AX 



= C1-C2. 



This leads to the second differential equation 
dC2 



,ci 

.C2 



dX 



= C1-C2. 



The two differential equations form a linear system of 
differential equations with the following solutions 
CI =C1 e" 

C2 = Clo X e * + C2o e * . 
When X = l. Cl = 1 and C2 = 1. we have CI = .36788. 
C2 = .73576. □ 

References 

1 1 1 Priorities In School Mathematics, National Council of Teachers of 

Mathematics, funded by the National Science Foundation, directed by 

Alan Osborne. Available from the ERIC Documentation Reproduction 

Service. P.O. Box 190. Arlington. VA 22210. 

|2| Greenspan. Donald. Arithmetic Applied Mathematics. Peritamon 

Press. Elmsford. New York. 1980. 




120 



"/ believe Franklin is having another brainstorm. " 

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CIRCLE 152 ON READER SERVICE CARD 




Evan Heit 

You are a tree. As a tree, your primary 
goal in the forest is to survive. But you are 
a human tree. As you know, human trees 
are very special trees with very special 
goals. You must be the tallest tree in the 
forest. At all costs. Even if some of your 
friends get hurt in the process. If you're 
impulsive, youll try to shoot way up in the 
air with no root or leaf system. And die. 
But if you're a wise tree, you'll grow upwards 
slowly, developing leaves and roots to supply 
you with more energy. So you can shoot 
up and be the tallest tree in the forest. 

The Situation 

You are a tree in the Floppy Forest. 
The Floppy Forest Social Director, Mr. 
Leaf Erickson, decides to hold a contest 
for all the little sprouts in the Forest. The 
Who-Can-Grow Five-Meters-First? Contest. 
Only you and four other seedlings are brave 
enough to try. At the beginning of the first 
year of the contest, you receive a letter 
from the local utility company, Con 
EdiSUN: 

YOU NOW HAVE 100 UNITS OF 
ENERGY. HOW MUCH DO YOU WANT 
TO ALLOW THIS YEAR FOR: 

1. PROTECTION AGAINST BUGS AND 
DISEASE? 

2. UPWARD GROWTH? 

3. LEAF GROWTH?. 



Evan Heit. 3530-15 Long Beach Rd.. Oceanside. 
NY 11572. 



4. DOWNWARD ROOT GROWTH? 

5. HORIZONTAL ROOT GROWTH?— 

You quickly fill out the form. You allow 
20 units for your long climb upward and 
twenty five units for the leaves, since your 
energy supply from now on will be based 
totally on the size of your leaf and root 
systems. You allow 15 units for downward 
root growth, twenty five for horizontal 
root growth, and the rest for protection. 
You seal the envelope, lick the stamp, and 
run down to the post office. And wait. 
And grow. 

122 



The Game 

Tree is for up to five humans. The 
computer will play for any tree not con- 
trolled by a human. You start with 100 
units of energy. Future energy supplies 
are based on the size of your root and leaf 
systems. You must have leaves and roots 
in order to make energy. Leaves without 
roots give no energy; roots without leaves 
are just as useless. Vertical growth supplies 
no energy, but serves as a base for horizontal 
growth. There is a 15% chance every year 
of damage due to disease or insects. The 
more you put away for protection, the less 
you will be damaged. The first tree to 
reach five meters wins. 

The Program 

Tree is written for the Commodore PET 
with 8K or more memory. Converting the 
program and graphics to other computer 
systems is possible. Everything is done in 
tiny subroutines to make things easier for 
you to understand (easier for me to write!) 

Notice that I almost always use extra- 
long variable names to express each vari- 
able's job. Those who don't get their jollies 
by typing extra stuff can reduce wear and 
tear on their fingers by typing a line like 

123 WIJABU(FOO) = VAL(BASKET- 

BALL$(6,BAH)) 

as 

123 WI(FO)=VAL(BA$(6,BA)). 

Here's a blow by blow description of the 
program: 

100-998 Calls the various subroutines of 

the program 

450 Checks for the end of the game 

950 Goes back for another year 

998 Lines like this don't have to be typed 

in 

1000-1998 Initialization 

1005 DIM's arrays 

ABOVE$(15) Fifteen lines on screen 

for above-ground growth 

BELOW$(15) Eight lines on screen 

for below-ground 

CREATIVE COMPUTING 



CBM/PET? SEE SKYLES ... CBM/PET? 



"Should we call it Command-O 
or Command-O-Pro?" 

That's a problem because this popular ROM is 
called the Command-O-Pro in Europe. (Maybe 
Command-O smacks too much of the military.) 

Bui whatever you call ii, this 4K byte ROM will provide your CBM BASIC 4.0 (4016, 
4032) and 8032 computers with 20 additional commands including 10 Toolkit program 
editing and debugging commands and 10 additional commands Tor screening, formatting 
and disc Hie manipulating. (And our manual writer dug up 39 additional commands in the 
course of doing a 78-page manual!) 

The Command-O extends Commodore's 8032 advanced screen editing features to the ulti- 
mate. You can now SCROLL up and down, insert or delete entire lines, delete the char- 
acters to the left or right of the cursor, select TEXT or GRAPHICS modes or ring the 
8032 bell. You can even redefine the window to adjust it by size and position on your 
screen. And you can define any key to equal a sequence of up to 90 key strokes. 

The Command-O chip resides in hexadecimal address $9000, the rightmost empty socket 
in 4016 and 4032 or the rearmost in 8032. If there is a space conflict, we do have Socket- 
2 Ml- available al a very special price. 

skslrs guarantees >our satisfaction: if you are not absolutely happy with your new 
Command-O, return it to us within ten days for an immediate, full refund. 

Command-O from Skyles hlectrk Works $75.00 

Complete with Socket-2-Me 95.00 

Shipping and Handling (USA/Canada) $2.50 (Europe/Asia) $10.00 

California residents musi add 6ft/6'/i1t sales tax. as required. 

{ ) Skyles KleCtrk Works \ isa Mastercard orders: call lollfree | 

yt 231K South vshisman Road (HOOl 227-9998 (except California). 

_ Mountain \ iew, California 94041 California orders: please call (415) 

gm* I-»I5> 965-1735 965-1735. 



/LAiaO ■■■ S31A>.S 33S clBd/IAiaO '" </> 



CBM/PET? SEE SKYLES ... CBM/PET? 



"You mean this one little 
Disk-O-Pro ROM will give my 
PET twenty-five new commands? 

And for just $75.00? Why, that's only $3.00 a command!" 

The l)isk-( t-l'ro in an. PET with Version III (BASIC 2.0) ROMs (### COMMODORE 
BASIC***) will give 19 software compatible disk instructions*: 15 identical with the new 
BASIC 4.0 (or with 8032 ROMs) compatible with both old and new DOS. Plus 4 addi- 
tional disk commands. . including appending (MKR(iK), overlaying (MKRCiK # ) 

and PRINT USING, allowing formatting output of strings and numbers on the PET 

screen or on any printer. 

'NOTE: Old DOS doesn 'I recognize three of the commands. 

Those are just 3 of the important commands — and there are 7 more beauties— on 
your Disk-O-Pro that have never been available previously to PET/CBM users. (Skyles 
does it again!) . . . Beauties like the softtouch key (SET) which allows you to define a key 
to equal a sequence of up to 80 keystrokes; like SCROLL whereby all keys repeat as well 
as slow scrolling and extra editing features; like BEEP which allows you to play music on 
your PET. 

The Disk-O-Pro is completely compatible with the BASIC programmer's Toolkit. The 
chip resides in the socket at hexadecimal address $9000. ihe rightmost empty socket in 
most PETS. And for the owners of "classic" (or old) PETS, we do have interface 
boards. 

(For those owning a BASIC 4.0 or 8032, even though the Disk-O-Pro may not be suit- 
able, the Command-O is. Just write to Skyles for additional information. Remember, we 
have never abandoned a PET owner.) 

Complete with 84-page manual written by Greg Yob. . who was having so much fun 
that he got carried away. We had expected 32 pages. 

Skyles guarantees your satisfaction: if you are not absolutely happy with your new 
Disk-O-Pro ROM chip, return it to us within ten days for an immediate full refund. 

IHsk-O-Pro from Skyles Electric Worka $75.00 

Complete with interface board (for "classic" PETS) 95.00 

Shipping and Handling (USA /Canada) $2.50 (Europe/ Asia) $10.00 

i California residents must add 6%/6l4% sales tax. as required. 
Skyles Electric Works Vl*»/Masterc«rd orders: call lollfree 
23IE South vs hisman Road (800) 227-9998 (except California). 
Mountain View, ( alifornia 94041 California orders: please call (415) 
(41$) 9*5-1735 965-1735. 



/lAiaO ■■ S31A>IS 33S 6.L3d/l/\iaO "' c/> 



NEED 



"BASF 

MEMOREX 

ODysan 



Visa. Masterchargc accepted Call 
free (800)235-4 1 37 for prices and 
information All orders sent postage 
paid 



PACIFIC 
EXCHANGES 

inn Foothill Blvd 
Sin LuisObtspo. CA 
'Iv401 (InCal call 
43-1037) 




CIRCLE 169 ON READER SERVICE CARD 



CIRCLE 184 ON READER SERVICE CARD 



AUGUST 1981 



123 



MASTERTYPE 

A Game That Teaches Typing 




Now you can leorn to type while 
playing a game on your APPLE II. In 
MASTERTYPE, enemy words are at- 
tacking your base. You must type the 
words in order to repel and destroy the 
attackers. You get to see what you 
type in the center box. but if you take 
the time to look at your fingers you will 
probably be destroyed. Learning to 
type used to be incredibly dull and 
boring. MASTERTYPE makes it fun. 

The MASTERTYPE diskette comes 
complete with 17 lessons taking you 
from simple letters through punctu- 
ation marks, plus a program for mak- 
ing your own lessons To order your 
copy, send check or money order for 
$34.95 to: 
MASTERTYPE 

P.O. Box 5223. Stanford. CA 94305 
Specify 13 or 16 sector (16 is default). 
Requires Applesoft (not the cassette 
version) and at least 32K. 

CIRCLE 223 ON READER SERVICE CARD 



Tree, continued... 

TURN(5,5) Each tree's turn in five 

categories 

ENERG Y(5) Each tree's energy 

HEIGHT(5), RHEIGHT(5) Height 

above and below ground 
1015 Fills ABOVES & BELOWS with 39 
spaces 

1035 NH is the number of humans play- 
ing 

1065 FIRST determines who goes first 
1070 Everybody starts with 100 units of 
energy 
2000-2998 Plan each year's turn 

2250 Human inputs her turn 
2400 Display human's energy 
2500 Computer makes its turn 

3000-3998 BUGS & DISEASE 
301 5 Fifteen percent chance of damage 
3020 Disease or insects? 
3030 How much damage? 
3035 Did tree allow enough for protec- 
tion? 
3040 Reduce unprotected trees 

4000-4998 Above-ground growth 

4013 Winner? 
4250 Vertical growth 
4255 How much energy to grow 1 /3 of a 
meter? 

4262 Don't grow upwards too fast! 
4500 Horizontal growth 
4520 Tree grows leaves— unless some- 
one's in the way 

5000-5998 Below-ground growth (see 
above) 

6000-6998 Display forest 

6025 Print stem and leaves of tree 

6050 Print roots of tree 

7000-7998 How much energy for each 

tree? 

7010 Less roots or less leaves? 

7014 How much energy? 

7018 Reduce old parts of tree 

8000-8998 A winner!! 
8010 Display trees 
8020 And the winner is... 
8025 Game over! 

9000-9998 INPUT ROUTINE-a return- 
proof input routine that won't drop you 
into Basic 

10000-10090 Here we decipher those 
inscrutable cursor control characters 
(you don't have to type this in) 

Back to Reality 

Your height is about 4^ meters, but 
your buddy next-door is a little bit taller. 
DAMAGE DUE TO DISEASE! Next year 
your damaged opponent doesn't budge at 
all. but since you put energy aside for 
protection, you grow a full meter with no 
damage. YOU WIN! □ 



a rem ****#**********«*********««* 

1 REM * *TREE* PROGRAMMED BY 

2 REM * EVAN K. HEIT 

3 REM * 3530-13 LONG BEACH ROAD 
» REM * OCEANS IDE, NV 11372 
3 REM » (SIC* 536 8063 

6 REM # AS OF OCTOBER 4, 1980 

7 REM # FOR ANV PET 8k « UP 
3 REM tS*t$t******$$tS$$$ttSt*ttttt 
9 

160 GOSUB1000 REM INI TIALIZATION 
200 GOSUB20OO REM TURNS 
300 GOSUB3000 REM INSECTS * DISEASE 
400 GOSUB40O0 REM ABOVE GROUND GROWTH 
450 IF BVEBVE-1 THEN END 

500 GOSUB5000 REM BELOW GROUND GROWTH 

600 GOSUB6OO0 REM DISPLAY 

700 GOSUB 7000 REM AVAILABLE ENERGY 

950 G0T0208 

998 

1000 REM"IMITIALIZATION 

'HI rIM *SOVE*<13.',BEL0W*<8>,TURNC5<5,',EfCRGV<3>.HEIGHT<3>,RHEIOHT<3> 

1010 PRINT".-J",TAB<17>,"srTREE" 

1015 FORJ=1T015 F0RK-1T03 AB0VE»< J>«AB0VE*<J>+" "NEXT NEXT 

1020 F0RJ-1T08 FORK-1T03 BELOW»<J,>BELOW*<J>*" » NEXT wxt 

1025 J-RNDOTI, REM RANDOMIZE 

1030 PRINT"MM»HOW MANV HUMANS ARE PLAYING (6-5V, GOSUB9000 NH-IN 

1035 NH«INT<ABS<NH>> IFNH<0ORNH>5THEN1030 

1060 PRIHT"»W»FIRST TREE TO REACH 5 METERS WINS'" 

1065 FIRST»INT<2»RND<1>*1> REM ORDER OF TURNS 

1070 F0RJ-1T05 ENERGY < J >« 100 NEXT 

1075 F0RJ»1 TO2O00 NEXT 

1080 RETURN 

1998 

2000 REM "TURNS 

2005 PR I NT" .Tl!" 

2010 YEAR- YEAR* 1 

2015 FIRST-3-FIRST 

2020 IFFIRST-1THEN2050 

2025 F0RJ-1T05 

2030 IFJ>NHTHENGOSUB2300 GOTO2040 

2035 GOSUB2250 

2040 NEXTJ 

2045 RETURN 

2050 F0RJ-5T01STEP-1 

2055 IFJ>NHTHENGOSUB2500 GOTO2065 

2060 GOSUB2250 

2065 MEXTJ 

2070 RETURN 

2250 REM HUMAN TURN 

2255 PR I NT " ."JaPL AVER " , J QQQ-ENERG V < J >■ GOSUB240O 

2260 PR I NT "HOW MUCH FOR PROTECTION", GOSUB90O0 TURN< J, 1 >.IM 

2265 QQQ»QQQ-IN JFQQCK0THEN2250 

lilt J^^t 9 ? FRIN T" H0W MUCH F ** UPWARD GROWTH", GOSUB9000 TURN<J,2>-IN 

2275 QQQ-QQQ-IM IFQQCK0THEN2250 

2280 GOSUB2400 PRINT"HOW MUCH FOR LEAF GROWTH"; GOSUB90O0 TURN'J, 3.>-IN 

2285 QGQ-QOQ-IN IFQ0CK0THEN2250 ««im«otw IUKN< J, 3->-IN 

2290 GOSUB2400 PRINT-HOW MUCH FOR DOWNWARD ROOT GROWTH", GOSUB90O0 

2295 TUR1KJ,4.>«IN OQO-QGQ-IN I FQQCK0THEN2250 

2300 GOSUB240O PRINT-HOW MUCH FOR HORIZONTAL ROOT GROWTH", GOSUB =000 

2305 TURN<J,5>-IH QQQ-QGQ-IN IFQUO<0THEN2250 

2310 PRINT"M«aRNV CORRECTIONS^' 

2315 RETURN 

2400 REM DISPLAY ENERGY 

2405 PRIHT"«lS»rr'OU NOW HAVE" ;QQG 

2410 RETURN 

2500 REM COMPUTER TURN 

2505 E 1 -ENERGY <. J > 

2310 TURN<J,2,>=;E1.'4>*RND<.1^+E1^6 

2515 E1=E1-TURN<J,2; 

2520 TURN< J, 3>--'<El/4^*RHIt< 1 ;*E. 

2525 E1-E1-TURN<.J,3.> 

2530 TURN <: J , 4 • = < E 1 ,'4 > *RNii i,*El/6 

2535 E1-E1-TURNCJ,4^ 

2540 TURH<J,5->»<E1. J *RND< 1 >*El/2 

2545 E1'E1-TURN,J,5; 

2550 TURNO, 1 £1 

2555 RETURN 

2998 

3000 REM" INSECTS * DISEASE 

3005 IFVEAR-1THENRETURN REM NO DISEASE IN FIRST YEAR 

3010 VUCK«-"" 

3015 IFRND<1><.85TH£NRETURN REM 15fc CHANCE 

3020 VUCK«-" DISEASE" I FRND < 1 X. 5THENVUCK*-" INSECTS" 

3025 FORJ-1T05 HEIGHT<J>-HEI0HTCJ>-1 NEXT 

3030 DAMAGE »60*<RND<i;>t2> 

3035 F0RJ-1TO5 IF<<TURN<:j,n + .3>«2»-DAMAO THEN3043 

3040 RATI0-DAMAGE/<<TURN<J,1>*.3>*2> HEIGMT< J>-HEIOHT< J>/RATI0 



GOSUB900O I FLEFT* < I US , 1 > « " - " THEN2230 



"II UMTS OF ErJERuV.JB" 



124 



CREATIVE COMPUTING 



Spelling Errors? 
Does yourTRS-80* wordprocessor need help? 



p%d*bi 



CAN SPELL rendezvous AND mnemonic 
AND OVER 38,000 OTHER WORDS 

Now let your TRS-80 and Proofreader by Soft-Tools check your Scripsit*, 
Electric Pencil, or other documents for spelling and typographical errors. 
It has all of the features needed to meet your proofreading requirements. 



• Checks every single word of even your biggest document 

in under 5 minutes. 

• The 38,000 word dictionary is one of the largest available. 

• Dictionary can be easily extended to add more words such 

as technical terms or names. 

• All unknown words are listed on the screen and can be saved 

on a file for printing. 

• Works with almost any TRS-80 wordprocessor including 

Scripsit and Electric Pencil. 

• Comes with complete and easy to understand User's Manual. 

• Developed for the TRS-80 by a Ph.D. in Computer Science. 



MODEL-I Requires 32 K RAM. 1 disk drive , TRSDOS* or NEWDOS $54.00 

MODEL-II Requires 64KRAM.1 disk drive, TRSDOS Version 2.0 $109.00 

MODEL-HI Requires 32 K RAM. 1 disk drive. TRSDOS $64.00 

User's Manual only, specify model $3.00 

When ordering, specify model, memory size, number of drives. 



Other professional quality software tools available from Soft-Tools 
include: SOFT-SCREEN"'- a full screen text editor for the Model-II 
and III, Ratfor - a structured programming language pre-processor for 
FORTRAN, PP-Ratfor - an automatic program pretty printer for Ratfor, 
plus more in the coming months. Please call or write for more details. 




YW 



Orders sent postpaid by first class mail. 
Terms: Cash, check, money order, VISA, 
or MASTERCARD. NM residents add 4% tax. 
Dealer inquiries invited 

Proofreader, Soft-Tools, and Soft-Screen are trademarks of Soft-Tools. 
Trademark of Tandy Corporation 




©©TO-TOOk®' 



P.O. Box 339 
Dept. C 

Tijeras. NM 87059 
(505) 281-1634 
CIRCLE 262 ON READER SERVICE CARD 



the BEST 

lower case adapter 

hmncsL 





QRAPHWS t LOWER CASE CHARACTER GENERATOR 
FOR THE APPLE II COMPUTER 

$69.95 

♦ Normal fc Inverse Lover Case. 

♦ 2 complete character sets on board. 
♦Graphics character font built in. 
+ Expansion socket allows access to 

external character sets. 

♦ 2716 EPROM compatible char generator. 

♦ More supporting software, (on diskette) 

♦ Keyboard +Plus I Graphics tpius designed 
around the Lower Case +Plus. 

the BEST 

keyboard buffer 

te?sc._ 




* SHIFT KKY UTKK LOWE* CASK CONTROL 

$119.95 

♦ More buffer than others. 

♦ Clear buffer control. 

♦ SHIFT key entry of upper/lower case. 

♦ Easy CTL key access to special chars 
■ I " " < ) _ I \ D". 

♦ Allows BASIC programs with standard 
INPUT to support Lower Case without 
software modification. 






Tree, continued. 



P MICRO SVST6MS 

1791-G Capital 
Corona, CA 91720 
(714)735-1041 



INC 



3041 
3043 
3058 
3999 

1000 
)001 

4005 

■1010 

4813 

4015 

4020 

1025 

•1030 

4033 

4037 

4040 

4043 

4030 

4230 

4235 

4256 

4260 

4262 

4263 

4265 

4270 

4273 

4280 

4283 

4500 

4305 

4510 

4515 

4518 

4520 

1325 

1329 

4330 

4335 

4340 

4998 

5000 

5001 
9009 
5010 
3015 
3020 
3025 
5O30 
5035 
3546 
3998 
MM 

6689 

6010 

6015 
6020 
6025 
6030 
6935 
6O40 
6043 
6045 
6030 
6055 
COM 
6065 
6998 

7*000 

7005 
7010 
7014 
7016 
7018 
7020 
7025 
7998 
3000 

•MS 

5010 
3011 
3015 
8020 
8025 
3030 
•998 

wee 



F0RK-2T05 TURN<J,K>-TL«NCJ,K>/RflTIO NEXT 
RETURN 

REM"AB0VE GROUND GROWTH 

IFFIRST-1THEN4030 

F0RJ-1T05 

GOSUB4250 REM VERTICAL GROWTH 

IFBVEBVE-1 THENRETURN 

GOSUB4500 REM HORIZONTAL GROWTH 

NEXTJ 

RETURN 

F0RJ-5T01STEP-1 

GOSUB4250 

IFBVEBVE-1 THENRETURN 

GOSUB450O 

NEXTJ 

RETURN 

REM VERTICAL GROWTH 

NEEDED-14+12*HEIGHTCJ> 

OLD»HEIGHT<J) 

HEIGHT<J>==0LD*TURN<J,2>/NEEDED 

IFHEIGHTCI>>»15THEN8000 
F0RK-1T0HEIGHT<J> 

AB0VE*<K)-LEFT#<AB0VE»<K>.1*6«J>*CHR«48*J>*MID#<AB0VE*<K>,3*6*J> 

RETURN 

REM HORIZONTAL GROWTH 

IFHEIGHT<J><1 THENRETURN 

H-HEIGHT<J> NEEDED-6*H 

WIDTH-TURN. J, 3../NEEDED*. 5 IFWIDTH>5THENWIDTH-5 

IFW1DTH<1 THENRETURN 

F0RK-<2.5+6*J;-WIDTHT0O-<-6*J.'*WIDTH 

IFMID*<ABOVE*<H>.K, 1X>" "THEN4535 

SIZEO, 1 >."8I2E<J~ lTTl *"**- 

ABOVE*<H>-LEFT*< AB0VE*<H, - K-l ,*CHR*<48*J,*MID*<AB0VE«<H> , M-l > 
RETURN 

REM "BELOW GROUND GROWTH 

IFFIRST'l THEN5030 

FORJ-1 T05 

G0SUB5250 REM VERTICAL GROWTH 

GOSUB5500 REM HORIZONTAL GROWTH 

NEXTJ 

RETURN 

F0RJ-5TG1STEP-1 

G0SUB5250 

RETURN 

REM-DISPLAV 

IFVUCK*-»""THEN6020 

PRIIIT'TJaMDAMAGE DUE TO " . VUCK* 

FORJ-1TO400O NEXT 

PR I NT "."J", 

F0RJ-U5T01STEP-1 

PRIr.'TABOVE*<J,' 

NEXTJ 

SCALE*- " 5*»-*U-a»4>IHaW-jat3«lr-«M-'IC IW-llh Mil Uhat- " 

PRINT"*" ; SCALE* PRINT"*" ; TAB> 36; , SCALE* 

print" 3***'ii&^iti***t&±iii**Mmjmmu*itm4)mtmi^ma»i^^*" 

F0RJ-1T08 PRINT"S",tELOW*<J.. NEXT 
PRINTTAB<16.>, "VEAR", VEAR, 
FORJ-1TO9000 NEXT 
RETURN 

REM"AVAILABLE ENERGY 
F0RJMT05 

low-size< j, i , ifsize<j,2 • ;lgwthenlow-size<j,2:> 

ENERG V < J > - I NT < 1 6*L0W* VE AR+HE I GHT < J > + . 5 > 
I F J>NHTHENENERGV < J > --ENERGV C J>«1 . I 
F0RK-1T02 SIZE<J,IO>-SIZE<.J,»0*.75 NEXT 
NEXTJ 
RETURN 



REM"WINNER! 

HEIGHT<JJ=«15 Jl-J 

GOSUB6080 

PR I NT "."MM" 

PRINT" IT IS VEAR", VEAR 

PRINT")WLAVER".J1, "WINS '•' 

BVEBVE=1 

RETURN 



REM" INPUT ROUTINE 



9005 INPUT"»»r*M«",IN* 
9010 IN-VALCIN*; 
9015 RETURN 
9998 

10000 REM" ai REVERSE ON 
10010 REM"* REVERSE OFF 
10020 REM-D CLEAR SCREEN 
10830 REM"* CURSOR HOME 
1O040 REM"* CURSOR DOWN 
10050 REM'TI CURSOR UP 
10060 REM"M CURSOR RIGHT 
10O70 REM "II CURSOR LEFT 
10080 REM WIJABU ! ! 



CIRCLE 210 ON READER SERVICE CARD 



126 



CREATIVE COMPUTING 




SARGON II (Spracklens) The first 
great computer chess program! "We are 
impressed with the program's speed, its 
opening book, and its much improved end 
game . . . Save your money and buy 
SARGON D . . . " '80 Software Critique. 
Seven levels of play, and levels 0-3 play 
in tournament time. It has a randomized 
opening book for all seven levels of play 
through three moves. When setting up the 
board, the user can scan up and down, 
left and right. A special hint mode 
included at all levels of play but will 
suggest a good, but not necessarily the 
best, next move you can make. 
"03404. Apple II; "03410. 
OSI C1P; "03418, TRS 80; 
" 03440. OSI C4P; each tape, $29.95; 
"03408, TRS-80 Level II Disk; 
"03409, Apple II Disk; "03414, OSI 
C1P DteJc; *03444, OSI C4P Disk; 
"03484, C8P Disk; each disk, 
$34.95. 



REVERSAL (Spracklens) Winner of the 
software division of the First International 
Man Machine OTHELLO™ Tournament, 
this version of the 200 year old game 
Reversi features 27 levels of play and 
high -resolution color graphics. "07004, 
Apple II tape, $29.95; "07009, Apple 
II Disk, $34.95. 

BLACKJACK MASTER: A 
Simulator/Tutor/Game 

(Wazaney) BLACKJACK MASTER 
performs complex simulations and 
evaluations of any playing and betting 
strategies that you enter into the computer. 
"05303, TRS-80 Level II tape, 
$24.95; "05308, TRS-80 Level II 
Disk. $29.95. 



Available at your 
local computer store) 



MIND THRUST (Sackson and 
Wazaney) The first of its kind — an 
exciting game that lets you match wits with 
the computer! The object is to complete an 
unbroken chain across the board before 
your opponent, the computer. There's a 
special feature; you may switch sides 
whenever you wish and gain control over 
your opponent's pieces, but this means 
that the computer has control over your 
chain, as well. Every game is different. 
"07403. TRS-80 Level II, $16.95. 

Coming Soon. . . 

• TETRAD 

• GALAXY OF GAMES 

• KLONDIKE 2000 

• ASTEROID BLASTER 



Play With Tha Gameware Champs 

For Orders and Inquiries Call Toll Free 

HAYDEN HOTLINE 800-631-0856 




Apple to a tridmiiik of the Apple Computer Co Inc end to not affiliated with Hayden Book Co , Inc 

50 Essex Street, Rochelle Park, NJ 07662 



Inc. 



CIRCLE 206 ON READER SERVICE CARD 



w» 



^©(fDgytnnKiMj 1 




moil order 



formerly Computers 'R* Ui 



Of EM EVERY DAY 9 to 6 PST 

California. Alaska & Foreign orders (714) 696-AOAo 

Shipping information or Dockorders coil (714)698-0260 

Service Center and for Technicol Information (714) 460-6302 

TELEX 695-000 ANS:DETA REF:CCMO 



ORDER TOLL FREE 



. • • 



654-6654 



' Autt 



: computer 

5nzed Dealer 



ALL EQUIPMENT IS 
FCC APPROVED 



APPLE II PLUS 16K 1025 

APPLE II PLUS 48 K 

(APPLE Memory) 1 1 29 

APPLE II Stondord Models. . CALL 
DISK II DRIVE & CONTROLLER. 519 
This model include* DOS 3 3 16 sector 

TOP F1VI StlllRS 

longuoge System W/Poscol 379 

Silentype Printer W/lnterfoce 340 

Hayes Micromodem II 299 

Videx Videoterm ©0 w/gropNcs 269 

Z-80 Microsoft Cord 269 

APHI COMPUTUS MC 

Disk II Drive Only 439 

Integer or Applesoft II Firmwore Cord 1 45 

Grophics ToCHet 619 

Porollel Printer Interfoce Cord 135 

Hi-Speed Senol Interfoce Cord 1 35 

Smorterm 00 Column Video Cord 299 

MOUMTAW COMPUTIft MC. 

Music System < 1 6 Voices) 479 

A/D + D/A Interfoce 289 

Expansion Chassis 599 

Introl/x 10 Cont Cord 169 

Clock/Caiendor Cord 225 

Supertolker SD 200 239 

Rompius + Card 135 

Romwrrter Cord 1 49 

CALIFORNIA COMPUTIR SYSTT.MS 

Clock/Calendar Module 99 

GPIO IEEE 488 Cord 249 

Asynchronous Serial Interfoce Cord 1 29 

Centronics Porollel Interfoce Cord 99 
We carry oil CCS hordwore Please coll 

mac. APPII HAADWAKI 

1 6K Rom Cord Microsoft 1 59 
AOT Number*: KeypocKold or new kybrd) 1 1 

ALF 3 Voice Music Cord 239 

Alpha Syntoun Keyboard System 1399 

Corvus 1 0M0 Hard Disk CALL 

Lojer Lower Cose Plus 50 

Micro So Disk Drives CALL 

SSM AlO Senol/Porollel Cord A6T 189 

SupRTerminol 80 Col Cord 329 

SVA 8 inch Floppy Disk Controller 345 

Versownter Digitizer Pod 229 

WI HA VI MANY MOM ACCISOMU 

FOR TM APPII I M STOCK— 

►LIASI CAU OR WRIT! FOR A PRICI 1ST. 



A 

ATARI 

Mooa. 

000 16K 

*749 



E^- 



Atar. 400 16K 

610 Disk Onve 

4 1 Program Recorder 

050 Interfoce Module 

922 Thermo) Printer (40 col) 

625 Prtnter (60 col) 

Atari 1 6K Rom Module 

Atan Light Pen 

We ttocfc all Atart accessor*** & 



PRINTERS 



Anodex DP 9500 W/2k Duffer 
Anodex DP 9501 W/2K Duffer 
C Itoh Storwriter 25 CPS 
C Itoh Storwriter 45 CPS 
Centronics 737 
Epson MX 70 W/Grophics 
Epson MX 80 132 Col 
Poper Tiger IDS 445 W/Dot Plot 
Paper Tiger IDS 460 w7Dot Plot 
Paper Tigei IDS 560 W/Dot Plot 
Oume Sprint 5/45 Daisywheel 
Silentype w/lnterfoce for Apple M 
Wotonobe Digipiot 



VIDEO MONITORS 

Amdex/Leedex Video 100 12 D6W 13< 

Hitochi 13 Color 35< 

NEC 12 P31 Green Phospher CALi 

Ponosonic 13 Color 44< 

Sanyo 9 00W 15< 

Sanyo 12 OCiW 23< 

Sanyo 12 P31 Green Phospher 27< 

Sonyo 13 Color 41< 



Challenger 4P 


549 


C4PMF (Mini Floppy System) 


1599 


OP Model II 


099 


Sorgon II (DiSK or Cassette) 


35 


Fig Forth (Disk Only) 


69 


APPLE SOFTWARE 


DOS Toolkit 


65 


Appleplot 


60 


Tax Plonne' 


99 


Apple Wr.rer 


65 


Apple Posi 


45 


D J Portfolio Evoluotor 


45 


D i News Quotes Reporter 


85 


Apple Fortron 


165 


Apple Pilot 


129 


DOS 3 3 Upgrade 


49 


Music Theory 


45 


The Controller Dus Sys 


499 


MISC. APPLICATION) PACKASfS 




Visicoic (DOS 3 3) 


169 


Desktop Plan II 


169 


CCA Doto Monogement DMS 


85 


Eosywnter Word Processoi 


225 


ASCII Express 


65 


Super Text II 


139 


Progrommo Apple Pre 


119 


The Landlord Apt Mgmt Pkg 


649 


Peochtree Business Software 


CALL 


Tax Preparer by HowordSoft 


69 


Applebug AsserrvDisossm/Editor 


75 


3D Grophics Dy Dili Dudge 


53 1 


4AMES 




Flight Simulator 


34 


The w.zord and The Princess 


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24 


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32 


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39 


Adventure by Microsoft 


27 


Phontoms Five 


39 1 


Reversol (Othello) 


34 


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FOR A COMPLITt 




SOFTWARE LIST. 





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tronsfer Credit 
pi rod on dote) 



CIRCLE 140 ON READER SERVICE CARD 



Lloyd Johnson 



A Futuristic Trade Simulation Game 



It seems that interstellar trade takes us back to the days of 
the Yankee Clipper. Return with us now to those thrilling 
days of tomorrow... 



Historical Background 

Early in the 26th century, the 50XFTL drive was developed. 
This drive, when properly installed on a spaceship, would 
cause a controlled warping of space enabling the spaceship to 
travel at fifty times the speed of light (50XFTL). Massive 
colonization of the nearby stars took place in the following two 
centuries, due to the crowded conditions on inhabitable 
planets of the solar system and the development of this drive. 

By the mid 29th century, large orbiting space stations (star- 
ports) were constructed at the ten most populated star sys- 
tems. These starports had facilities for docking and refueling 
starships as well as massive cargo storage capability. The 
construction of these starports was closely paralleled by a 
simplification of starship design. With the advent of the star- 
ports, it was no longer necessary for a starship to land on a 
planet. This eliminated the need for atmospheric streamlining, 
as well as the large reaction engines required to lift the starship 
from the planetary surface, while it substantially increased the 
cargo hold of starships. 

The type of cargo which will be available for purchase at 
any particular starport is difficult to predict, since most of the 
cargos did not originate at that star system, but were brought 
there by other merchant starships. Coordination of trade 
routes to guarantee cargo availability at a starport had never 
occurred due to the independent nature of the star merchants 
and the slow communication between the star systems. 

As trade developed between the starports, each starport 
was assigned a trade classification. Although the trade classifi- 
cation is useless in determining which cargos might be avail- 
able for purchase, it is extremely useful in predicting the price 
of the cargo. 

Game Description 

When you play Star Merchant you will find yourself com- 
mander of a merchant starship. Your goal is to make enough 
money by trading cargos to stay in business and regain your 



Lloyd Johnson. I IM7 Silhouette PI.. Florissant. MO 6.10.1.1. 



initial investment for the lease of the starship. There are ten 
different starports where trade is conducted and 36 different 
types of cargos which may be traded. A brief set of instructions 
for the game is listed in lines 90-260 of the program and is also 
listed in the sample run. 

The different types of cargos range from agricultural pro- 
duce and raw materials to industrially produced items, such as 
weapons and machinery. The price at which these cargos will 
be traded is dependent upon the trade classification of the 
starport where the item is being traded. For example, farm 
machinery might bring top dollar at a starport with an agricul- 
tural trade class, whereas the price of grain there will probably 
be very low. 

The starport names, distances and directions listed for com- 
mand 5 (LIST STARPORTS) were taken from the actual 
names, distances and direction of some of the stars closest to 
Earth. The distance and direction will not always be com- 
pletely accurate, since for this game the stars are represented 
on two dimensions, as opposed to three dimensions of actual 
space. (There is assumed to be a good scientific reason for 
this. -Ed.) 

Ship expenses must be paid every time a new starport is 
reached. If your account becomes negative after paying these 
expenses, you must sell enough cargo to make it positive 
before you can leave the starport. If you do not have enough 
cargo to do this, you are out of business and the game ends. 

The expenses which must be paid consist of a docking fee, 
fuel expenses, and crew salary. The docking fee will always be 
50,000 credits. The fuel expenses are directly proportional to 
the distance traveled from the last starport. The cost of fuel 
per lightyear is 100,000 credits. The crew's salary is based on 
an annual salary of 500,000 credits and the amount of ship time 
that has passed since the crew was last paid. Ship time 
increases approximately .02 years a week for each lightyear 
traveled and approximately .003 years a day for each cargo 
transaction. 

As your fortune grows, the probability increases that the 
crew will go on strike for a higher salary. When a strike occurs 
the crew presents their salary demands and you are asked for a 
counter-offer. The probability that your counter-offer will be 
accepted depends upon the amount that you offer and the 
number of counter-offers that have been rejected previously. 
Once the crew has rejected ten counter-offers, they will accept 



AUGUST 1981 



129 



Star Merchant, continued. 



100 - 



90 —I 
Percent 
chance 
counter 

offer 8° ■ 

will be 
accepted 

70 ■ 



60 - 



50 _ 



40 — 



30 _ 



20 - 



10 - 




Number of counter 
offers rejected 



Present 
salary 



Amount of salary counter offer 



Salary 
demanded 



Fiuiire 



only their original salary demands or higher. For this reason an 
early strike settlement is desirable. 

The lease on your ship will expire after two years of ship 
time. At this time you will be asked to renew your lease if you 
have enough money. It will cost 2,000.000 credits for another 
two-year lease. Should you decide not to renew your lease, or 
if you do not have enough money for lease renewal, the game 
will end, and the game results will be displayed. 

A copy of the program on cassette for the TRS-80 Level II 
computer may be obtained from me for $10. 

Program Description 

This program is written in H-P Basic. With little or no 
modification it should work on most machines. To aid in 
debugging, a detailed description of the program and the 
variables follows. 



The program is arranged into five main sections. These 
sections and their corresponding subsections are listed as 
follows: 

1. Initialize section. Lines 50-630. 

2. Main logic section. Lines 640-880. 

3. End program section. Lines 890-1030. 

4. Subroutine section. Lines 1040-3640. 
4.1 Strike. Lines 1040-1230. 

List cargo in hold. Lines 1250-1410. 

List cargo for sale. Lines 1420-1580. 

Buy cargo. Lines 1590-1890. 

Sell cargo. Lines 1900-2040. 

List starports. Lines 2050-2140. 

Travel to new starport. Lines 2150-3370. 

List commands. Lines 3380-3460. 



4.2 
4.3 
4.4 
4.5 
4.6 
4.7 
4.8 



130 






CREATIVE COMPUTING 



High-Resolution Color Graphics 
for the Apple and Atari 



Graphics 
Breakthrough 




How many programs have you written 
that would benefit from animated high- 
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Exceptionally powerful software 

It is in the software where VersaWriter 
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Here a shape (the letter At is being 
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it may be used in other programs. 




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Create Animation for Other Programs 

The shapes you create with VersaWriter 
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Toll-free 800-631-8112 

(In NJ 201-540-0445) 



CIRCLE 239 ON READER SERVICE CARD 



Star Merchant, continued. 



4.9 Restore READ statement to star data. Lines 
3470-3520. 

4.10 Restore READ statement to cargo data. Lines 
3530-3580. 

4.1 1 Restore READ statement to price data. Lines 
3590-3640. 

5. Data section. Lines 3650-4620. 

5. 1 Star names. Lines 3650-3750. 

5.2 Cargo names. Lines 3770-41 20. 

5.3 Star data. Lines 4130-4230. 

5.4 Cargo Data. Lines 4240-4600. 

5.5 Price data. Lines 4610-4620. 

The initialization section displays game instructions, initial- 
izes variables, seeds the random number function, and sets up 
the initial voyage from Alpha Centauri to Sol. (This initial 
voyage is necessary in the program logics since the statements 
that determine which cargos are for sale are contained in the 
travel to new starport subroutine.) 

The main section is responsible for performing the follow- 
ing tasks: 

1. Determining whether a strike is to occur. 

2. Accepting a command and calling the appropriate sub- 
routine. 

3. Determining whether the player has run out of money. 

4. Determining whether the ship's lease has expired. 
Control is tranf erred to the end section if the player runs out of 
money, if the lease on the ship expires and the player does not 
renew it, or if the lease expires and the player does not have 
enough money to renew it. If none of these conditions occur, 
control will be passed back to the beginning of the main 
section. 

The end section prints out the end conditions of the game 
and transfers program control to the end statement. 

The subroutine section contains subroutines which are 
called from both the initialization section and the main sec- 
tion. With the exception of subroutine 4.7 (travel to new 
starport), all subroutines are called by the line number listed at 
the beginning of the subroutine. 



The ship time, player's account 

balance and available cargo space 

will be updated upon completion 

of the cargo transaction. 



Upon entering the strike subroutine, the salary demands of 
the crew are calculated by adding from zero to fifty percent of 
their current salary to it. The minimum salary the crew will 
accept is then calculated from their current salary, their 
demanded salary, and the number of counter-offers which 
have previously been rejected. The minimum salary that the 
crew will accept will initially be equal to their current salary 
and will increase by ten percent of the difference between 
their salary demands and their current salary for each counter- 
offer that is rejected. The probability that a counter-offer will 
be accepted may be represented as a separate linear function 
for each number of counter-offers previously rejected. These 
functions are graphed in Figure 1 . 

The subroutines that list the cargos for sale and the cargos in 
the hold use the contents of arrays A and H respectively. A 
detailed description of these two arrays is included in the 



variable description. For each non-zero cargo type, the cargo 
name is obtained from the data section. This is done by doing a 
restore, followed by the required number of data reads neces- 
sary to position the data pointer to the cargo name that 
corresponds to the cargo. This cargo name along with other 
information in array A or H is then displayed with a PRINT 
USING statement. The PRINT USING statement and its cor- 
responding IMAGE statement will require some modification 
in order for it to work with other Basics. 

The subroutine for buying cargo consists of obtaining the lot 
number of the cargo to be purchased and transferring the 
corresponding data from the A array to the H array. The first 
empty position in the H array is used to store the cargo which 
has been purchased. The ship time, player's account balance, 
and available cargo space will be updated upon completion of 
the cargo transaction. 

The subroutine for selling cargo consists of obtaining the 
partition number of the cargo to be sold, and sets the corres- 
ponding position in array H to zero. This is done to indicate 
that the partition is now empty. Ship time, player's account 
balance and available cargo will also be updated. 

The list starport subroutine reads the starport name and 
trade class from the data section and displays them. Distance 
and direction for each starport will also be displayed, and 
stored in the arrays D and T respectively. The contents of 
these two arrays will have been previously calculated by the 
travel subroutine when it is executed. 

The travel (to new starport) subroutine performs the follow- 
ing tasks: 

1. Accept destination starport number and perform validity 
checks. 

2. Get trade and location data for destination starport. 

3. Appraise cargo stored in ship's hold. 

4. Determine type, price and quantity of cargos available for 
purchase at destination starport. 

5. Determine distance and direction of other starports from 
the destination starport. 

6. Calculate and display arrival expenses and destination 
starport's name. 

This subroutine is called each time the travel command is 
invoked, and also during program initialization. When this 
subroutine is called from the initialization section, the state- 
ments which accept the destination starport number are 
bypassed. 

The three subroutines which are used to restore the READ 
statement to a particular data section basically do a restore 
followed by successive reads until the corresponding data 
section is reached. 

The data section consists of the five types of data already 
mentioned. They are read as necessary. Each statement in the 
star-names section and the cargo-names section has a state- 
ment in the star-data section and the cargo-data section which 
corresponds to it. 

The first two parameters in a data statement for star data are 
the X and Y coordinates of that star, relative to Sol. These 
values may be altered if you want to change the position of the 
star. The third parameter corresponds to the trade class of the 
starport. This value is calculated by representing each trade 
class by a power of two (listed in Table 1 ). An example of the 
calculation for generating the trade class is as follows: The 
trade class for Alpha Centauri is NA and I. The parameter 
representing this trade class is thus 2 2 + 2\ which equals 9. 

The data statements for cargo data consist of eight parame- 
ters. The first six parameters are used in calculating the price 
of the cargo. If the trade class of the starport corresponds to 
the parameter, the value of the parameter will be added to 
the random number which determines the price. The trade 
class to which each parameter corresponds is listed in Table 
1. 



132 



CREATIVE COMPUTING 



^ Th e PROGRAM STORE sSftSHSfe 







For Apple II 
Apple II Plus 
Applesoft, «8K Disk 
unless otherwise noted 




By Bill Budge from BudgeCo 
If this program can't make the "Pinball Wiz 
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ALIEN RAIN 



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REVERSAL 



PULSAR II 




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Inspired by the popular "STAR CASTLE" ar 
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AUTOBAHN 

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Take on the world's fastest highway in your 
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Based on the 200 year old strategy game 
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r\ the 
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Visit Our Baltimore, MD Store: W. Bell Plaza- 66 OO Security Blvd 



S3 » TO ORDER CALL TOLL FREE 800 424-2738 



For information 
Call (202) 363-9797 



MAIL ORDERS: Send check or M.O. for total purchase 
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information on card. 



THE PROGRAM STORE 

4200 Wisconsin Avenue NW, Dept. RA2Box 9609 
Washington, D.C. 20016 

CIRCLE 1 75 ON READER SERVICE CARD 



Star Merchant, continued 

Trade Class 



Rich 

Poor 

Industrial 

Nonindustrial 

Agricultural 

Nonagricultural 



Power of Two 


Parameter 


5 


1 


4 


2 


3 


3 


2 


4 


1 


5 





6 



Table I. 



A(5,4) 



Bl 

B2 
B3 

D(10) 



D2 

D3 
D4 
D9 
El 
E2 
E3 
E4 

E5 
E6 

E7 
Gl 

H(20,4) 



I 

J 

K 

L 

Ml 

M2 

Nl 

N2 

N3 

N4 

P(14) 



P2 



01 



Available cargo for purchase. First subscript refer- 
ences one of the five available cargos. 
Ail.l I represents the cargo type of available cargo 

I . Value is set to zero when cargo I is purchased. 
All, 2) represents the price of cargo I. 
A 1 1.3) represents the weight of cargo I in tons. 
Ai 1 .4) represents the price of cargo I as a percent- 
age of its base price. 
Base price of a cargo. Value for Bl is read from the 
data statements. 

Amount of money in player's account. 
Player's total assets. Equal to B2+T1. 
Distance in lightyears from player's present loca- 
tion to each of the ten starports. D(5) is initialized to 
4.3 for initial journey from Alpha Centauri to Sol. 
Price modifier calculated from cargo trade modi- 
fiers and starport trade class. 
Cargo trade modifiers read from data statements. 
Distance to the destination starport. 
Dummy variable. Value is never used. 
Docking expense. Initial value is 5E4. 
Fuel expense for light year traveled. Value is 1E5. 
Annual salary of crew. Initial value is SE5. 
Amount of crew's salary paid upon arriving at a 
starport. 

Salary demands of crew. 

Minimum counter-offer crew will accept during a 
salary strike. 

Amount of salary counter-offer. 
Average annual profit gain calculated at the end of 
the game. 

Cargo stored in ship's hold. First subscript refer- 
ences the cargo hold partition number. 
Hil.l) represents the cargo type in partition I. 

Value is set to zero when partition is empty. 
H(I,2) represents the price of the cargo in partition 

H(I,3) represents the weight of the cargo in parti- 
tion I. 

H( 1.4) represents the percentage of the base price 
the cargo in partition I has been appraised at. 

Temporary variable. 

Temporary variable. 

Temporary variable. 

Temporary variable. 

Trade class parameter of Starport. 

Variable used in unpacking trade class parameter. 

Ml. 

Number of cargos available for purchase. 

Number of cargo types. Initialized to 36. 

Number of starports. Initialized to 10. 

Number of counter-offers that have been rejected. 

Percentage values read from data statement. Used 

in modifying the base price of a cargo. 

Percentage index. Values may range from 1 to 14. 

Used to index PI 14) to determine the percent of 

base price at which the cargo will trade. 

Quantity index of a cargo type, as read from cargo 



02 



03 
Rl 

S(6) 



SI 

T(10) 

Tl 

T2 

T5 

T6 

T7 
Wl 
W2 

XI 
X2 

X3 
Yl 
Y2 

Y3 



data. Represents the number of times a random 
between 1 and 6 is used to generate the quantity. 
Quantity multiplier. Random number used in gen- 
erating cargo quantity is multiplied by Q2. 

Q2 = 1 for cargo types 1 through 16. 

Q2 = 5 for cargo types 17 through 31. 

Q2 = 10 for cargo types 32 through 36. 
Quantity of cargo in tons. 

Argument for random number function. Set equal 
to zero. 

Array containing the trade class of the destination 
starport. Value is either 1 or 0. 
S(l) = 1 implies starport is rich. 
S(2) = 1 implies starport is poor. 
S(3) = 1 implies starport is industrial. 
S(4) = 1 implies starport is nonindustrial. 
S(5) = 1 implies starport is agricultural. 
S(6) = 1 implies starport is nonagricultural. 
Destination starport for starship. Initialized to 5. 
Direction in degrees of all ten starports. 
Total value of cargo stored in the hold. 
Cargo type. 

The number of times the ship's two year lease is 
renewed. 

Elapsed ship time in years. 
Ship time when crew was paid. 
Total cargo capacity of ship. Set to 200. 
Amount of empty cargo space on ship. Initially set 
equal to Wl to indicate an empty cargo hold. 
Starport's X coordinate relative to Sol. 
Starport's X coordinate relative to present position 
of ship. 
X coordinate of destination star relative to Sol. 

Y coordinate of starport relative to Sol. 

Y coordinate of starport relative to ship's present 
position. 

Y coordinate of destination star relative to Sol. 




"Frankly. I liked the old games belter. " 



134 



CREATIVE COMPUTING 



IOL\ HAM 

PERSONAL 
COMPUTER 

Only 

$24900 

Special Factory Sale Price 




THE EDUCATIONAL COMPUTER 



• Learn to program a computer 

• Learn to operate a computer 

• For Students 

• For Hobbyists 

• For the Professional 

• For Small Business 

• For the Home Owner 



WHAT A SMART INVESTMENT !! 



QUALITY COMPUTER AT A 
PRICE ANYONE CAN AFFORD 

Great for learning to program and operate a 
computer, with all kinds of features built in for 
students, hobbyist, the professionals, small 
business and homeowners. It has a powerful 
8080A intel microprocessor brain. 16K Dyna- 
mic RAM, 2K ROM, Real time, a High Speed 
Cassette Deck that operates at 1500 Baud; 
loads and reads 5 times faster than most com- 
pacts, it has a full 53 typewriter layout key- 
board. The graphics are 8 colors with 77 x 112 
resolution, text display is 1 2 lines of 1 7 charac- 
ters, it also has sound and color, includes an AC 
adapter, power cord, R. F. modulator, TV 
switch box and 8' connector cable. It is FCC, 
CSA approved and UL listed. All this built into 
an attractive black console plastic case. Comes 
in sturdy shipping carton that measures 20" 
long x 12" wide and 8" depth. Weighs 16 lbs. 



AN INCOMPARABLE 
SCHOOL TEACHER 

Prepare yourself for the future! You can learn 
to operate and program a computer for job 
opportunities in the computer revolution. 
Our Level II basic is equivalent to all Level II 
Programs currently available. This basic in- 
cludes a super set of operations in floating 
point with integer and string arrays, direct 
memory access, PEEK and POKE, direct 
statement execution, two character variable 
names, user definition functions, multi-state- 
ment lines, editing, scrolling, file management 
and morel 808A MACHINE LANGUAGE AND 
EDITOR PROGRAMS ARE AVAILABLE. 

Since the computer can talk, play music and 
perform in color IT IS A PHENOMINAL TEA- 
CHER. You can now use the TV to EDUCATE 
not frustrate your family. You will eliminate 
TV boredom with programs that challenge, sti- 
mulate and entertain you. Create your own pro- 
grams or select from over 30 programs offered. 
IT IS A BRILLIANT MUSIC TEACHER. You 
can practice on the piano keyboard . overlay, 
select key and tempo, write a tune and record. 
It has a great color art program, you can im- 
prove your memory, math, spelling, vocabulary 
and sharpen your strategy skills. IT IS A 
GREAT TUTOR FOR YOUR KIDS. 



USE AS A BUSINESS TOOL 

Although the Interact MODEL "R" is not 
designed for business, the Level II basic and the 
16K Byte system give you room to write your 
own programs for individual business needs. We 
also offer these business programs: Calculator, 
Check Book Balancer, Stock Portfolio, Mort- 
gage & Loan and Message Center. 



IT ALSO PLAYS GAMES 

A total entertainment center with color, sound, 
and music. There are Chess, Backgammon, 
Star Track, Black Jack, Volleyball, Touchdown, 
Hangman, Showdown, Computer Maze, Break- 
through and morel Challenge the computer or 
another opponent. Each game brings the family 
and friends together for hours of quality fun. 

SERVICE AND WARRANTY 

If the unit fails because of factory defect within 
90 days of purchase, it will be repaired at no 
charge for labor and parts - you just send the 
unit United Parcel prepaid to the Service Center 
designated and it will be sent back to you 
within 48 hrs. United Parcel prepaid! A com- 
plete Diagnostic program tape and instructions 
are available. You can get a Service manual. 
Cassette alignment tape. Schematics, and parts 
list plus a Money Saver Service and warranty 
Card. Everything you need to check and ser- 
vice your computer. 

IT CAN BE EXPANDED AT LOW COST 

It is a single board computer. RS232 Interface 
is available. Telephone modem $139. 80 col- 
umn Regular Paper Printer $499. You can 
access "Micronet," "Source" and other data 
banks. You can talk to other computers. Our 
factory sponsored National Computer Club 
membership allows discounts on all tape 
programs. You can learn from other owners 
the fantastic things you can do with this 
computer through exchange of technical and 
programming information. 

PRICE COMPARISON 

Competitive 16K RAM Personal Computer 
Suggested List prices are: Radio Shack $849, 
T.I. $695, Atari $1,125, Apple $1,195, Ohio 
Scientific $850. Radio Shack's TRS-80 that 
has only 4K RAM, sells for $399. 



WHY SUCH A LOW PRICE 

Selling on a factory direct to customer basis, 
we save you the profit normally made by com- 
puter stores and distributors. You also save the 
cost of a computer monitor as this computer is 
FCC approved and designed to hook up to any 
TV antenna terminal. We are willing to take 
a small margin at the factory to develop volume 
that allows lowest cost operation. 



SPECIAL FACTORY SALE $249.00 

You get the Interact MODEL "R" computer 
that includes 16K RAM, 2K ROM, 8080A 
microprocessor, color, sound, full 53 key board, 
high speed cassette deck, power cord, AC adap- 
tor, connector cord rack, tape storage tray, 8' 
connector cable, R.F. modulator with TV 
switch box and owner's manual. 

SPECIAL FACTORY PACKAGE 
SALE DEAL $344.00 

Everything you get for $249.00 plus: LEVEL II 
DOCUMENTATION: Level II user's manual. 
Level 1 1 Basic Program Tape, Level 1 1 Command 
Cards, Level II Basic Examples Book. SERVICE 
AND WARRANTY PACK: Diagnostic Program 
Tape, Diagnostic Instruction Manual, Service 
Manual, Cassette Head Alignment Tape, Sche- 
matics and Parts List, Money Saver Service 
and Warranty Card. Two 8 AXIS ACTION 
CONTROLLERS with Pot Knob, Firebutton 
and Lever. PLUS THREE TAPE PROGRAMS. 
(Everything you need to learn to operate, 
program and service your computer.). 

FREE TRIAL OFFER - RETURN WITHIN 

IS DAYS UNITED PARCEL PREPAID 

COMPLETE AND UNDAMAGED FOR FULL 

REFUND OF PURCHASE PRICE. 



DON'T MISS THIS SALE - ORDER NOW 

D Please send me the model "R" 16K 
RAM computer for $249.00. 

D Please send me the SPECIAL FACT- 
ORY PACKAGE PRICE DEAL FOR 
$344.00. 

Add $1 5.00 for shipping and Insurance. 
Illinois residents add 6% tax. 

ENCLOSE CASHIER'S CHECK, MONEY 
ORDER OR PERSONAL CHECK. Allow 
14 days for delivery. 21 days for personal 
cneck orders. 10 days for phone orders. 

We ship c.O.D. We honor Visa and Master 
Card orders. 



Name 



AddtuM 


Cltv 


State 


zm 


D Visa 
Card No. . 


O Master Charge Q C.O.D. 



Exp.. 



ENTERPRIZES 



(FACTORY - DIRECT RELIABILITY! 



BOX 550, BARRINGTON, ILLINOIS 60010 - Phone 312/382-5244 to order 

CIRCLE 180 ON READER SERVICE CARD 5M5-81 



Sensibly 
Priced 

A new stand-alone 
Paper Tape Reader 




Parallel TTL 

interface "***■ 

150 CPS reading/ 

bi-directional 
Stops on character 
Includes power supply 

and reader 



x 



ADDMASTER 

CORPORATION 

416 Junipero Serra Drive 

San Gabriel, California 91776 

(213) 285-1121 



CIRCLE 103 ON READER SERVICE CARD 



FREE SOFTWARE 

Well, practically free 
just the cost of a diskette 

I have over 700 programs 

for the Apple 
both Integer and Applesoft 

Send me a disk with a few 

(5 or more) 

of your favorite programs 

and a check for 

SS.OO 

Tell me what your interests are 
Games. Finance, Business, Other 

I will fill a disk with at least 20 

of my favorities and return it 

postage paid 



BUCK'S SOFTWARE SWAP 

C/O KIRBY 

1S05 KIRK WOOD 

GARLAND, TEXAS 75041 

CIRCLE 104 ON READER SERVICE CARD 



RG0 
BLE. 



Star Merchant Sample Run 

STAR MERCHANT 
YOU H»VE JUST SPENT 2 MILLION CREDITS ON A 2 YE»R 
LEASE FOR A MERCHANT STARSHIP. THIS LEAVES YOU WITH 
2 MILLION CREDITS OPERATING CAPITAL. 

YOUR SHIP CAN HOLO A TOTAL OF 20 CARG0S WITH A TOTAL 
CARGO WEIGHT OF 200 TONS. THE FUEL CAPACITY OF YOUR 
SHIP IS GREAT ENOUGH SUCH THAT TRAVEL BETWEEN Amy 
T.Y0 STARPORTS IS POSSIBLE WITHOUT REFUELING. 

YOU ARE PRESENTLY TRAVELING FROM ALPHA CENTAI1RI TO SOL. 
YOU ARE CARRYING NO CARGO. 

THE STARPORT TRADE CLASSIFICATION DETERMINFS THE CAR 
PRICE BUT DOES NOT DETERMINE WHICH CARGOS ARE AVAILA 

ABBREVIATIONS USED FOR TRADE CLASS ARE AS FOLLOWS! 
»-R I CH.P-POOR, I -INDUSTRIAL. NI-NONTNDUSTR I »L. 
A>AGRICULTURAL>NA-NONAGRICULTURAL 

PRESS RETURN TO CONTINUE7109 
COMMANOS AVAILABLE ARE AS FOLLOWSI 

COMMAND DESCRIPTION 

1 LIST CARGO IN HOLO 

2 LIST CARGO WHICH MAY «E PURCHASED 

3 BUY CARGO 

• SELL CARGO 

5 LIST STARPORTS 

* TRAVEL TO NEW STAR 
OTHER LIST AVAILABLE C0MMAN1S 

INPUT A RANDOM NUMBER BETWEEN 1 AND S007I09 



YOU HAVE ARRIVEO AT SOL 

E»PENSES HAVE BEEN OEOUCTEO AS FOLLOWS! 

DOCKING FEE 50000. 

FUEL 430000. 

CREW SALARY 53000. 



ACCOUNT BALANCE I . 46T00E ♦Oh 
SHIP TIME .106 YEARS. 

CARGOS AVAILABLE FOR PURCHASE 
CARGO NUM DESCRIPTION 

1 LIQUOR 

2 RADIOACTIVES 

3 GRAV SLEDS 

• ELECTRONIC PARTS 
5 POLYMERS 

ACCOUNT BALANCE l.o»,70OE*0h 
SHIP TIME .106 YEARS. 



EMPTY CARGO SPACE 200 
ENTER COMMAND?? 



AMT 
25 

6 

4 

5 

40 



PRICE 



X OF BASE 



175000 ISO 

S400ono 90 

31200000 MO 

750000 150 

146000 TO 



EMPTY CARGO SPACE 200 
ENTER COMMAN073 



ENTER THE LOT NUMBER OF CARGO YOU WISH TO PURCHASE?* 
TRANSACTION COMPLETED 
CARGO STORED IN PARTITION I 



ACCOUNT BALANCE 1.27100E*06 
SHIP TIME .109 YEARS. 



STAR NUM 
I 

2 
3 
4 
5 
6 
7 
B 
9 
10 



NAME 
LALANOE 21145 
ALPHA CENTAURI 
SIRUS 

BARNAROS STAR 
SOL 

ROSS 154 
EPSILON ERIDANI 
LUYTEN 726-8 
LUYTEN 789-6 
ROSS 24B 



EMPTY CARGO SPACE 160 
ENTER C0MMANn?5 



TRADE CLASS 0I3TANCE DIRECTION 
NI,P 
NA.I 
A 

I.P 
R 

NI.NA 
A,P 
NA 



A,NI,' 
A.I 



7.89 


291 


4.24 


236 


12.99 


50 


6.10 


1B0 


0.00 


90 


9.10 


167 


10.75 


38 


B.00 


68 


10,30 


115 


10.30 


95 



ACCOUNT BALANCE I.27I00E»06 
SHIP TIME .109 YEARS. 



EMPTY CARGO (PACE 160 
ENTER C0MMANP76 



ENTER DESTINATION STAR NUMBER72 

YOU HAVE ARRIVED AT ALPHA CENTAURI 

EXPENSES HAVE BEEN DEDUCTED AS FOLLOWSI 

DOCKING FEE 50000. 

FUEL 429344. 

CREW SALARY 54434.4 

ACCOUNT BALANCE 737222. EMPTY CARGO SPACE 160 
SHIP TIME .214869 YEARS. ENTER COMMAND?! 



136 



CREATIVE COMPUTING 



CARGO STOREO IN HOLD __ 

PARTITION DESCRIPTION AMT PRICE * OF BASE 

1 POLYMERS «" 676000 170 

ACCOUNT BALANCE 737222. EMPTY C»R60 SPACE 160 
SHIP TIME . 210*69 VE»RS. ENTER C0MMAND?4 

ENTER PARTITION OF CARGO TO IE SOL0?1 
TRANSACTION COMPLETED 

THE CRF* MAS BONE ON STRIKE 

YOU ARE CURRENTLY PAYING TMEM 500000. 

THEY ARE ASKING FOR 747858. CREDITS ANNUAL SALARY 

ENTER COUNTER OFFER7660000. 
1FFER ACCEPTED 



CREDITS ANNUALLY 



EMPTY CARGO SPACE ZOO 
ENTER COMMAND?? 



AMT 

too 

20 

165 

5 

5 



PRICE 

51000 

2100000 

198000 

32499995 

2000000 



I OF BASE 

170 

TO 
400 
110 

40 



ACCOUNT BALANCE 1.2IS22E*06 
SHIP TIME .21T869 YEARS, 

CARSOS AVAILABLE FOR PURCHASE 
CARGO NUM DESCRIPTION 

1 GRAIN 

2 COMPUTER PARTS 
1 GRAIN 

4 GRAV SLEDS 

5 AIRCRAFT 

ACCOUNT BALANCE 1.21322E*06 
SHIP TIME .217*69 YEARS. 

ENTER THE LOT NUMBER OF CARGO YOU HISM TO PURCHASE?! 
TRANSACTION COMPLETED 

C»»SO ST0M9 IN PARTITION I 

ACCOUNT B4L4AICE 1.162221*06 
SHIP TI«* .22»»»)9 YEARS. 

STAR Nil* NAME 

1 L»LANOE 21145 

2 ALPHA CENTAUR! 

3 SIRUS 

4 S6BNAR0S STAR 

5 SOL 

6 ROSS 154 

7 EPSILON ERIOANI 

8 LUYTEN 726-4 
4 LUYTEN 744-6 

10 ROSS 248 



EMPTY CARGO SPACE 200 
ENTER COMMANO?S 



EMPTY CARGO SPACE 100 
ENTER COMMAN0?5 



TRAOE CLASS OISTANCE OIRECTION 



N!,P 

NA.I 

A 

I.P 

R 

NI.NA 

A.P 

NA 

A.NI.P 

A.I 



6.46 

0.00 

17.27 

5.11 

4.29 

8.56 
14.40 
12.21 

13.02 
13.40 



324 

40 
51 

136 
56 

134 
43 
64 
99 
44 



ACCOUNT BALANCE 1.I6222E»06 
SHIP TIME .220864 YEARS. 



EMPTY CAR60 SPACE 
ENTER C0MM*N0?6 



100 



ENTER DESTINATION STAR NUMBER?4 

T1U HAVE ARRIVED AT BARNARDS STAR 

EXPENSES HAVE BEEN OEOUCTEO AS FOLLO«SI 

T1CKIN6 FEE 50000. 

F'JEL 513455. 

CRE« SALARY 84936. 

ACCOUNT BALANCE 313831. EMPTY CARGO SPACE 100 
SHIP TIME .34356 YEARS. ENTER COMMAND?! 

CARGO STOREO IN HOLD 

PARTITION DESCRIPTION »MT PRICE » °^ 9 *" 
6RMN 100 36000 120 



ACCOUNT BALANCE 513831. 



EMPTY CARGO SPACE 100 



SHIP TIME .34336 



YEARS. 



ENTER COMMAND?? 



CARGOS AVAILABLE FtlR PURCHASE 
CARGO NUM DESCRIPTION 

I BOOT ARMOR 

I CRYSTALS 

J MECHANICAL PARTS 

4 GRAV SLEDS 

5 CYBERNETIC PARTS 



AMT 

6 

I 
20 

3 
13 



PRICE 

300000 

10000 

1030000 

16400000 

1500000 



I OF BASE 
100 
50 
70 
60 
40 



ACCOUNT BALANCE 513831. EMPTY CARGO »P»CE 100 
SHIP TIME .34356 YEARS. ENTER C0MMAN0?3 

ENTER THE LOT NUMBER OF CARGO YOU HISH TO PURCHASE?2 
TRANSACTION COMPLETED 
CARGO STORED IN PARTITION 2 

ArCOUNT BALANCE 503831. EMPTY CARGO SPACE 49 

Sh" TIP* .mm* *e»ps. ""■ co--.No?s 

ENTER THE LOT NUMBER OF CARGO YOU HISH TO PURCHASE71 
TRANSACTION COMPLETED 
CARGO STOREO IN PARTITION 3 



©®TnrR<Q(£ 

PACKER Machine language program that edits all or 
part ot your Basic program to run (aster save ™ IT *> r y 
or ease editing The 5 options include UNPACK - 
unpacks multiple statement lines into single statements 
maintaining logic inserts spaces and renumbers lines 
SHORT -deletes unnecessary words spaces and REM 
statements PACK -packs lines into maximum multiple 
statement lines maintaining program logic RENUM- 
renumbers lines, including all branches MOVE-moves 
line or blocks ot lines to any new location m program 
On 2 cassettes tor 16K. 32K. A 48K For TRS-BO™ 
Mod I or III Level II or Disk Basic $29 95 

SYSTEM TAPE DUPLICATOR Copy your SYSTEM 
format tapes Includes verily routines The Model III 
version allows use ot both 500 and 1 500 baud cassette 
speeds 

For TRS-80™" Model I or III Level II $15 95 

CASSETTE LABEL MAKER A mini word processor 
to print cassette labels on a line printer Includes 50 
peel-and-stick labels on tractor teed paper 
For TRS-80™ Model I or III Level II » Printer $17 95 
PRINT TO LPRINT TO PRINT Edits your Basic program 
in seconds to change all Prints to LPrints (except 
Prints or Printui or LPrmts to Prints Save edited 
version 

For TRS-80'" Model I or III Level II $1? 95 

FAST SORTING ROUTINES For use with Radio 
Shacks Accounts Receivable Inventory Control I, 
and Disk Mailing List Systems tor Model I Level II 
Sorts in SECONDS' You II be amazed at the time they 
can save Supplied on data diskette with complete 
instructions .,~~. 

FAST SORT lor Accounts Receivable $ 1 9 95 

FAST SORT lor Inventory Control I $ 19 95 

FAST SORT lor Oisk Mailing List I specify data diskette 
cassette tor 1 drive system | $ 1 4 95 

ALL THREE ROUTINES »4« 95 

Prices subject to change without notice Call or write 
tor complete catalog Dealer inquiries invited VISA 
and MasterCard accepted Foreign orders in US 
currency only Kansas residents add 3% sales tax 
On-line catalog on Wichita FORUM-80 316-682-21 13 
Or call our 24 hour phone 316-683-481 1 or write 
COTTAGE SOFTWARE 
614 N Harding Wichita. KS 67208 
TRS-80 is a trademark ol Tandy Corporation 



CIRCLE 161 ON READER SERVICE CARD 



SO FTWARE 



... FOR THE 

T.I. 99/4 COMPUTER 



Enjoy the fascination of sports; 
the stock market; entertainment; 
modern warfare and more with 
FUTURA 

FUTURA is Now! Write today for 
your free catalog and sample 
program. 

Available in both Tl and Extended 
Basic. 

DEALER INQUIRIES INVITED 



Ehninger Associates. Inc. 

PO Box 5581 

Fort Worth, Texas 76108 

817 246-6536 



CIRCLE 173 ON READER SERVICE CARD 



Games 
Wanted 




^^^^^^m 



Hayden Book Company. Inc., 
the publisher of SARGON II, is 
once again accepting sophisti- 
cated and interesting new game 
submissions for ALL home com- 
puters. 

If you have a game which you 
would like us to consider for 
national and international pub- 
lication, please contact: 

Stephen Radosh 

Games Editor 

Hayden Book Company, Inc. 

50 Essex St. 

Rochelle Park, NJ 07662 

CIRCLE 20S ON READER SERVICE CARD 



MEMOREX 
DISKETTES 

cr 

CARTRIDGES 

for your computer or word processor 



BUY THE BEST FOR LESS 
Lowest prices. WE WILL 
NOT BE UNDERSOLD!! Buy 

any quantity 1 - 1000. Visa, 
Mastercharge accepted. Call 
free (800) 235-4137 for prices 
and information All orders 
sent postage paid 




CIRCLE 169 ON READER SERVICE CARD 



Star Merchant Program Listing 



10 

■>« 

10 

40 

•50 

60 

70 

40 

90 

100 

110 

120 

U0 

1*0 

ISO 

160 

170 

ISO 

190 

200 

210 

220 

230 

2*0 

250 

260 

270 

2*0 

290 

500 

510 

120 

ISO 

340 

ISO 

160 

170 

190 

190 

400 

410 

420 

410 

440 

4S0 

460 

470 

460 

490 

500 

510 

520 

510 

540 

550 

560 

570 

560 

S90 

600 

610 

620 

610 

640 

650 

660 

670 

6S0 

690 

700 

710 

720 

710 

740 

750 

760 

770 

740 

790 

600 




REM 

REM STAR MERCHANT 
REM BY LLOYD JOHNSON 

REM * • * 

REM INITIALIZE SECTION 

3IM AS1201.BS18I,A|S.«1.0I10|,M120,«I 
DIM PM41.SI6I.T1101 
PRINT TAB(20)"STAR MERCHANT' 
MNT -YOU HAVE JUST SPENT 2 MILLION CREDITS ON A 2 YEAR- 
LEASE FOR A MERCHANT STARSHIP. THIS LEAVES YOU H1TM" 
■2 MULION CREDITS OPERATING CAPITAL." 



PRINT 
PRINT 
PRINT 
PRINT 
PRINT 



Ir?«« SM i P C * N M0L0 * T0T * L ° r ™ C»R60S NITH A TOTAL" 
T °,; E ^Ir°c 20 ° T0N8 * THt ' U «- CAPAC TY OF YOUR" 
PR NT MM «!!»£» ^ 6H SUCH ™* T "*"" "ETNEEN ANY" 
T TM STARP0RTS IS POSSIBLE WITHOUT REFUELING." 



PRINT 
PRINT 
PRINT 
PRINT 
PRINT 
PRINT 
PRINT 
PRINT 
PRINT 



3S 111 SSSSS^JTSP "°" * L ' M * " NT4URI T ° S0L '' 

IIo!,? T * BP0BT T "* 0E CLASSIFICATION DETERMINES THE CARGO" 
"PRICE 8UT DOES NOT DETERMINE NHICH CARG0S ARE AVAILABLE. 



Io"=^ VI » T,0NS USE0 F0R TR * 0E CL *« "»* *» FOLLONSt" 

PRINT "A-AGRICULTURAL.NA-NONAGRICULTURAL" 

PRINT "PRESS RETURN TO CONTINUE*! 
INPUT AS 

rnl?.l I«!! ^ * N0, * V »"-ABLE ARE AS F0LL0M," 
GOSUB 3380 

LET R1«0 

PRINT 

INPUT I INPUT * *" N00M N " M «R BETWEEN 1 AND 500"| 
PRINT 

FOR Jal TO I 

LET OVaRNDtRl) 

NEXT J 
DEF FNA(R1»«INT(6«RND(R1))*I 
DEF FNR(N2)aINT(N2»RND(RI))*l 
DEF FNC(RI)«FNA(R1)»FNA(R1) 
LFT B2a2.00000E»06 m • 



LET 015184.3 
LFT SlaS 
LET E1850000. 
LET E2al00000. 
LET E38500000. 
LET N2a36 
LET NSalO 
LET Nla200 
LET «2aNl 

FOR 181 TO 20 
LET Hd.llaO 
NEXT I 
GOSUB 3590 

FOR Ia| TO IB 
READ P til 
NEXT I 
LET TSaO 
LET T6a0 
LET TTaO 
GOSUB 2280 
REM MAIN LOGIC 

IF RND(RI)».01*.005*B2/E3 THEN 670 
GOSUB 1040 
PRINT 
PRINT "ACCOUNT BALANCE "»B2|"EMPTY CARGO SPACE 

,!*\ !? M " TIME "» T *'"»EARS. ENTER CD-MAN0 

INPUT C 1 

PRINT 

rn.. C ,i*!.! N0 C,<7 * N0 ClaINT(ABS(CI)) THEN 750 
GOSUB 5380 

GOTO 640 

, G rr U a. C l °' ' 2a0 '» «*<>»> "0 , 1 900 , 2050 , 2 1 50 

LET 83aTi8c?*Tl 

IF 63<0 THEN 890 

IF T6»2*T5<2 THEN 640 

PRINT 

PRINT "THE LEASE HAS EXPIRED ON YOUR SHIP" 




"|H2 
'I 



138 



CREATIVE COMPUTING 



MO 

*?0 

430 

440 

450 

460 

470 

440 

490 

400 

910 

9?0 

ISO 

940 

9?0 

960 

970 

940 

990 

1000 

1010 

1020 

1030 

to«o 

1050 

\ObO 

1070 

1080 

1090 

1100 

1110 

1120 

1130 

1140 

1150 

1160 

1170 

1140 

1190 

1200 

1210 

1220 

1230 

1240 

1250 

1260 

1270 

12S0 

1290 

1300 

1310 

1320 

1 <10 

1 340 

1350 

1360 

1370 

1340 

1390 

1400 

1410 

1420 

1430 

1440 

1450 

1460 

1070 

1 440 

1490 

1500 

1510 

1520 

1530 

1540 

1550 

1560 

1570 

1560 

1590 

1600 

1610 

1620 

1630 

1640 

1650 

1660 

1670 

1660 



IF B3«2.00000E»06 THEN S90 
PRINT "ANOTHER TNO YEAR LEASE 4ILL COST 2C6 CREDITS" 
PRINT "DO YOU DISH TO RENEW YOUR LEASE(V/N)"| 
INPUT AS 

IF AS«*N" THEN 890 
LET 42»B2-2.00000F*06 
LET T5»T5*1 
GOTO 640 
REM ENO PROCRAM 
LET GW83-«.OOOOOE»06)/T6 
LET AS»"LOSS" 
IF GMO THEN 940 
LET AS«*6AIN" 
IF SS»0 THEN 970 
PRINT 

PRINT "YOU NO LONGER HAVE SUFFICIENT FUNDS TO OPFRATE YOUR SHIP' 
PRINT 

PRINT "YOU STARTED KITH 4E6 CREOITS" 
PRINT "YOU NOW HAVE "|82 
PRINT "CARGO IN HOLD IS WORTH " I T 1 
PRINT 

PRINT "THIS REPRESENTS A "|AS|" OF * SGI 1 "CREDITS PER YEAR" 
GOTO 4630 
REM STRIKE SUB 
PRINT 

PRINT "THE CREW HAS GONE ON STRIKE* 

PRINT "YOU ARE CURRENTLY PAYING THEH • I E3| "CREDI TS ANNUALLY" 
LET E5pE3».5*RND(R1)*E3 

PRINT "THEY ARE ASKING FOR * lE5l "CREDITS ANNUAL SALARY" 
LET N4«0 

LET EbaE3*N4*(E5-E3)/10 
PRINT 

PRINT "ENTER COUNTER OFFER"! 
INPUT ET 

IF E7 >■ E5 THEN 1210 
IF E7«E6 THEN 1180 

IF (E5-E7)/(E5-E6XRND(R1) THEN 1210 
PRINT "OFFER REJECTED - TRY AGAIN" 
LET N«aN4*l 
GOTO 1110 

PRINT "OFFER ACCEPTED" 
LET E3«E7 
RETURN 

REM LIST HOLD 

PRINT "CARGO STORED IN HOLD" 
IF «2<wt THEN 1290 
PRINT "ALL PARTITIONS ARE EMPTY" 
RETURN 

PRINT "PARTITION DESCRIPTION AMT"| 
PRINT ■ PRICE t OF BASE" 
FOR I«l TO 20 
RESTORE 

IF HU.llaO THEN 1400 
FOR jal TO 19«H(I,11 
READ AS 
NEXT J 
READ AS 

PRINT USING 1390lI.AS.H|I,31 ,H(I,21 ,M(I,41 
IMAGE 3»,2D,5X.18A,2X,30.2«.90,4»,3O 
NEXT I 
RETURN 

REM LIST CARGO FOR SALE 
PRINT "CARGOS AVAILABLE FOR PURCHASE* 
IF N1»0 THFN 1470 

PRINT "ALL AVAILABLE CARGOS HAVE BEEN PURCHASEO* 
RETURN 

PRINT "CARGO NUM DESCRIPTION AMT"| 
PRINT " PRICE X OF BASE" 
FOR lal TO 5 
RESTORE 

IF All.llaO THEN 1570 
FOR Jal TO l9»AtI.U 
RFAO AS 
NEXT J 
READ AS 

PRINT USING 1390(1, *S, A (I. 31 , A [1,21 .A [I, 41 
NEXT I 
RETURN 

REM BUY CARGO SUB 

PRINT "ENTER THE LOT NUMBER OF CARGO YOJ WISH TO PURCHASE"! 
INPUT K 

IF KaARSdNT(K)) ANO K>0 AND K<6 THEN 1650 
PRINT "INVALID LOT NUMBER" 
RETURN 

IF A(K,I1>0 THEN 1680 

PRINT "LOT *|K|*HAS BEEN ALREADY PURCHASED* 
RETURN 
IF A (K,21 <a B2 THEN 1710 



Real Estate Programs 

I or \ppli- II or I RS-M 

Property Management System 

*:h. I DKk Swieiml 



Features 

• Tenant Information 

• Late Rent Reports 

• YTD & Monthly Income 

• Handles — 

Partial Payments 
Returned Checks 
Advance Payments 

• 5 Digit Expense Accounts 

• Building Expense Report 

• Vendor Expense Report 

• Income Tax Report 

• AM Reports Can Be Printed 

• Complete Documentation 

• Easy Data Entry & Edit 

• ?00 Units per File 

Price $225.00 



\iiiil\sis Modules: 



1 Home Purchase Analysis 

2 Tax Deferred Exchange 

3 Construction Cost/Profit 

4 Income Property Cashflow 

5 APR Loan Analysis 

6 Property Sales Analysis 

7 Loan Amortization 

$35.00 Per Module 




1116 8th St . Manhattan Beach, CA 90266 
Suite F, Dept C 




AUGUST 1981 



139 



1 »OOt74 1551 
1CLES ON READER SERVICE CARD 



Time for Sorcerers 



Time Card 
Clock 



• houri, minutes, seconds 

• day. date, month, veer 

• * interval interrupts 

• * year backup battery 
TIME CARD interfaces with BASIC INP and OUT 
statements or simple machine language routines, which 
are included. TIME CARD plugs into the MICRO BOX or, 
with the bus cable, directly into the Sorcerer expansion 
port. Bus cable includes a mini enclosure, expansion 
bus cable, and 5 volt adapter cable to the Sorcerer. 
TIME CARD SIH.SJ, bus cable *]•.•> 



Micro Box 
Expansion 

:ro box is th 

Systems products. 



• • expansion bus slots 
e S volt power supply 
e daisy chain with disks 
e compact 
MICRO BOX is the foundation for future Triannle 
Systems products. Now In development ere memory 
boards, an EPROM programmer, seriel and parallel 10, 
and an AMD «SII math card. MICRO ROX pluns Into the 
Sorcerer expansion port and is fully buffered. IIM.N 

Triannle Systems products include tutorial manuals, 
available separately for S5.00 (nonrefundable, postaoe 
paid). Software on 1200 baud cassettes (transferable to 
disk) or Exldy disks. Hardware is guaranteed »0 davs. 

To Order: Specify softwere format (add $2. SO for 
disk), add SJ.00 domestic. Jf.00 overseas for shipping 
and handling. Ohio residents add 5.5* sales tax. Send 
payment In U.S. funds to: 

^7 Triangle Systems 

PO Box »»0 2* r.olumhus. Ohio 4)2*4 

Telephone •aas-Spia EST (•■*) 272-1241 

Sorcerer trademark of Exldy Systems, Inc. 



CIRCLE 237 ON READER SERVICE CARD 



Tarbell Double Density 
Floppy Disk Interface 

m * "'FOR 8" DISK DRIVES 

Under Tarbell Double-Density CP/M, single and double density 

disks may be intermixed. The system automatically determines 

whether single or double density is in place. 

'Software select single or double density. 

•Phase-locked-loop and write precompensation for reliable 
data recovery and storage. 

•On-board phantom bootstrap PROM is disabled after boot- 
strap operation so all G4K memory address space is available 
to user. 

• DMA in single or double density permits multi-user operation. 

• Extended addressing provides 8 extra address bits, permitting 
direct transfer anywhere in a 16 megabyte address range. 

• Select up to 4 drives, single or double sided. 

•New BIOS for CP/M included on single-density diskette. 



CP/M is a reg. trademark of Digital Research. 




950 Dovlen Place, Suite B.Carson, Ca. 90746 
(213)538-4251 (213)538-2254 



CIRCLE 202 ON READER SERVICE CARD 



Star Merchant, continued. 



1690 
I 700 

iTtn 

1720 
1730 
1 7<I0 
1750 
1760 
1770 
1780 
1790 
MOO 
into 
ti?o 

IMfl 

isao 

1850 
I860 
1870 
18*0 
1890 
1900 
1910 
1920 
19J0 
1940 
19S0 
I960 
1970 
t9S0 
1990 
7000 
2010 

2020 

203O 
2040 
»050 
2060 
2070 
-»080 
■>090 
2100 
21 10 
2120 
21 50 
2140 
2150 
>Mt0 
2170 

2180 
2190 
•>200 
2210 
2220 
2230 
2240 
2250 
2?60 
2270 
2280 
»290 
2300 
2310 
2320 
2130 
2390 
■>350 
2360 
2370 
2380 
2390 
2aoo 

2*10 
2*20 
2*30 
2*40 
2050 
2*60 
2870 
2880 
2490 
2500 
2510 
2520 
2530 
2540 
2550 
2560 



TRA1E CLASS'S 



140 



PRINT "YOU CANNOT 8UY CARGO ON CREDIT" 

RETURN 

IF MK.31 <■ «2 THEN 1740 

PRINT "TOU 00 NOT HAVE SUFFICIENT CARGO SPACE" 

RETURN 

FOR I«l TO 20 

IF Hd.llaO THEN 1790 

NEXT I 
PRtNT "ALL 20 CARGO PARTITIONS ARE OCCUPIED" 
RETURN 

FOR J«l TO 4 

LET Htl. J1«A [K.J1 
NEXT J 
LET »(K,11»0 
LET i»2»H2-Htt,31 
LET 82aB2>H(I,2) 
LFT T6«T6*.00S 
LET NHN1-1 

PRINT "TRANSACTION COMPLETED" 
PRINT "CARGO STORED IN PARTITION •»! 
RETURN 

RFM SELL CARGO SU8 

PRINT "ENTER PARTITION OF CARGO TO BF S1L0"| 
INPUT K 

TF KeABSdNTCK)) AND K»0 AND K<2! THEN I960 
PRINT "INVALID PARTITION NUMBER" 
RETURN 

IF HtK,l|»0 THEN 1990 
PRINT "CARGO PARTITION IS EMPTY" 
PFTURN 

LET R2»B2*H(K,21 
LET *2sw2»H(K,31 
LET T6»T6*.003 
LFT H'K.ll.Q 

PRINT "TRANSACTION COMPLETED" 
RETURN 

REM LIST STARPORTS SUB 
PRINT "STAR NIIM NAME 

PRINT " DISTANCE DIRECTION" 
RESTORE 

FOR TBI TO 10 

READ AS. BS 

PRINT USING 2120iI,AS,BS,Dlt) ,T III 

IMAGE 3X,20,fl»,20A,2x,|OA,30.20,9X,3n 

NEXT I 
RETURN 

RFM TRAVEL SUB 
IF 82>0 THEN 2190 
PRINT "YOU CANNOT LEAVE STARP0HT 

UNTIL ALL DEBTS ABC CLFAWF0" 
RETURN 

PRINT "ENTER DESTINATION STAR NUMHFR"j 
INPUT I 

IF I«SI THEN 2240 
PRINT "YOU ARE ALPF.A0Y AT "jl 
RETURN 

IF IsARS(INTd)) AND I>0 AND I«N3»I THEN 2270 
PRINT "INVALID STAR NUMBER" 
RFTURN 
LET SHI 

REM GET STAR TRADE * LOCATION DATA 
R0SU8 3470 
IF s 1 = 1 THEN 2340 

FOR I»1 TO (Sl-1)e3 

READ n9 

NEXT I 
READ X3.Y3.M1 

FOR I»l TO 6 

LET M2B2-f6-I) 

LET Stn«INT(Ml/M2) 

LET M1«M1.SII)*M2 

NEXT I 
REM APPRAISF CARGO IN HOLdI 
LET T1B0 

FOR I»l TO 20 .'J 

IF Htl.D.O THEN 2630 M 

G0SUB 3530 " 

IF Htl. list THEN 2490 

FOR J»l TO (H(I,1I-1)«8 
READ D9 
NEXT J 

LET 02*0 

FOR J«l TO 6 
READ 01 

LET D2.D2*DJ»3[JI 
NEXT J 

READ Bl .. • . 

LET P2»FNC(R1)*D2-1 

IF P2>1 THEN 2580 

CREATIVE COMPUTING 







2570 LET P2«l 

2580 IF P2<|« THEN 2600 

2540 LET P2«14 

2800 LET H(I,8)aP(P2)t>i00 

2610 LET m(I,2]«P!P21.«|.mii,11 

2*20 LET TliTl*HtI,2) 

2630 NEXT I 

26*0 PEM BET CARGOS FOR SALE 

2650 LET NJ»5 

2680 FOR 1*1 TO 5 

2670 LET 02«0 

2680 LET T2sFNB(N2) 

2690 LET AU,1)»T2 

2700 SOSUB 3530 

2710 IF T2»l THEN 2750 

2720 FOR J«l TO (T2-l>*8 

2730 READ 09 

2740 NEXT J 

2750 FOR J«l TO 6 

2760 READ D3 

2770 LET 02b02*03*SCJ) 

2780 NEXT J 

2790 L8T P2aFNC(Rl)*02-l 

2800 IF P2M THEN 2820 

2810 LET P2»l 

2820 IF P2«lo THEN 28*0 

2(130 LET P2«I8 

28*0 LET * tI.a).P(P2) «100 

2850 READ 81,01 

2*60 LET 02»1 

2«70 IF T2«17 THEN 2910 

2880 LET Q2»5 

2890 IF T2<32 THEN 2910 

2900 LET 02*10 

2910 LET Q3»0 

2920 FOR J»l TO 01 

2930 LET 03«FN*(R|)*02»03 

2980 NEXT J 

2950 LET MI,S1«Q3 

2960 LET A(I,21«8.t>Q3*P(P2i 

2970 NEXT I 

2980 REM DISTANCE AND DIRECTION OF STARS 

2990 LET DAaDtSll 

3000 GOSUB 3*70 

3010 FOR 1*1 TO 10 

3020 READ X1,Y1,D9 

3030 LET X2aXl»X3 

3080 LET T2PY1-T3 

3050 IF X2«0 THEN 3110 

3060 IP Y2«0 THEN 3090 

3070 LET TIIIMO 

3080 GOTO 3180 

3090 LET Til) "270 

3100 GOTO 3180 

3110 LET T[I]»ATN(Y2/X2)«180/3. 18159 

3120 IF X2>0 THEN 3180 

3130 LET T(I]bT(I!*180 

3180 IF TUM360 THEN 3160 

3150 LET T(I)*T(I)>360 

3160 IF T III »0 THEN 3180 

3170 LET T III BT tll*360 

3180 LET tIl»S0R(X2-2»Y2*2) 

3190 NEXT I 

3200 REM ARRIVAL EXPENSES AND STAR NAME 

3210 LET T6«T6*.02«08«.02 

3220 LET E8«(T6-T7)«E3 

3230 LET TT»T6 

3240 RESTORE 

3250 IF SKI THEN 3290 

3260 FOR 1*1 TO SKI 

3270 READ AS.RS 

3280 NEXT I 

3290 REAO »$.8» 

3300 PRINT 

3310 PRINT "YOU HAVE ARRIVED AT "|AS 

3320 PRINT -EXPENSES HAVE BEEN DEDUCTED AS F0LLONSI a 

3330 PRINT "DOCKING PEE "|E1 

3380 PRINT "FUEL "tE2«08 

3350 PRINT "CRE* SALARY "»E8 

3360 LET B2»B2-(EKE2«08»E8) 

3370 RETURN 

3380 PRINT TAB(5)|"C0MMAND"»TA»<25)»"DESCRIPTI0N" 

3390 PRINT TAB(8>,"l",TAB(25Jl"LIST CARGO IN HOLD" 

3400 PRINT TABf8>,"2"|TAi<25)t"LIST CARGO WHICH 

MAY BE PURCHASEO" 

3410 PRINT TAB(B)|"3"|TA8(25)|"BUY CARGO" 

3420 PRINT TAB(S) t*4"|TAB(25)l"3ELL CARGO" 

3430 PRINT TA»(8)l*5"lTABt25)l"LIST STARPORTS" 

3440 PRINT TAB(8)l*6'|TAB(25)l"TRAVEL TO NE" STAR" 



Here's the KEY 
to your Apple®! 




( nmpulrt Siafmn 

Ho nd book 



Computer 

Station's 
Programmers 

Handbook 

for the 

Apple® 



Retail Price 

29.95 



vie, if notebook I7 1 2" • 
containing rill the reference material found in our 
popular Programmers Guide to the Apple II ' 



Plus . . . 

• Applesoft' & Integer 

• CP M Digital 

Research. Inc 

• Basic-80 Microsoft 



• 6502 Assembly Language 

• DOS 3.3 

• DOS Tool Kit 

• Monitor 



Including Command References for 

Applewrlter' • Macro-Seed 

Visicalc Personal Software 

Hardware Configurations & 
Software Commands for 



Spinwriter 
PaperTiger 



• Silentype 

• Special ROMs 



Two diskette pockets in front & back Ni 
format .1 ments A 

must for every Apple' ownei Available from 

local Apple " I )eaiei 1 11 from 

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(314)432-7019 

ler will in< 00 shipping/handling 

arge plus sales tax where applicable 

Applr. Apple II and Applesoft are the registered trademarks of 
Applr Computer Im 



AUGUST 1981 



141 



CIRCLE 149 ON READER SERVICE CARD 



Star Merchant, continued. 



1450 PRINT TAB(6)|"0THER*fTAR(25)l a LIST AVAILABLE COMMANDS" 

1460 RETURN 

1470 REM RESTORE TO STAR DAT* SUB 

1480 RESTORE 

1440 FOR L»l TO (2*N3*N2) 

1S00 READ »» 

1510 NEXT I 

1520 RETURN 

1510 REM RESTORE TO CARGO DATA SUB 

1540 GOSUB 3470 

1550 FOR LBl TO 3«N3 

1560 READ D9 

1570 NEXT I 

1580 RETURN 

1590 REM RESTORE TO PRICE DATA SUB 

1600 COSUB 1530 

1610 FOR L»l TO 8«N2 

1620 READ 09 

1630 NEXT L 

1640 RETURN 

1650 REM STAR NAMES 

1660 DATA "L*L»N0E 21 185", "NI ,P" 

1670 OATA "ALPHA CENTAURI " , "NA , I ■ 

1660 OATA "SIRUS","A" 

1690 DATA "BARNAROS STAR", "I, P" 

1700 OATA "SOL","R" 

1710 OATA "ROSS 154","NI,NA" 

1720 DATA "EPSILON ERIOANI ", "A ,P" 

1710 OATA "LUYTEN 726-8", "NA" 

1700 DATA "LUYTEN 789-6" , " A , NI , P" 

1750 OATA "ROSS 248", "A, I" 

1760 REM CARGO NAMES 

1770 OATA -CRYSTALS" 

1780 OATA "RADTOACT1VES" 

1790 OATA "SPECIAL AL 

1800 OATA "PHARMACEUa 

1810 OATA "GFMSV^B 

?A?0 OATA "AIRCRAFT" 

1810 n»T« "CKAV SLEDS" 

<AO0 OAT» "CUMPUTERS" 

18S0 OATA "«TV" 

I860 HATA "«FV" 

<S70 OATA "FIKEARMS" 

1«80 DATA "AMMUNITION* 




1890 
1900 
1910 
1920 
1910 
1940 
1950 
I960 
1970 
1980 
1990 
4000 
4010 
a02O 
aOIO 
4040 
4050 
4060 
11070 
4080 
4090 
4100 
4110 
4120 
4110 
4140 
4150 
4160 
4170 
4180 
4140 
4200 
4210 
4220 
4230 
4240 
4250 
4260 
4270 
4280 
4290 
4300 
4310 
4320 



We don't play ha rd to get 



OATA 

DATA 

OATA 

OATA 

OATA 

OATA 

OATA 

DATA 

OATA 

DATA 

OATA 

DATA 

OATA 

OATA 

OATA 

DATA 

OATA 

OATA 

OATA 

DATA 

OATA 

DATA 

OATA 

DATA 

REM S 

OATA 

OATA 

DATA 

DATA 

OATA 

OATA 

DATA 

DATA 

OATA 

OATA 

REM C 

DATA 

DATA 

DATA 

OATA 

OATA 

OATA 

OATA 

OATA 



"PLASMA GUNS" 

"TOOLS" 

"BOOT ARMOR" 

•FARM MACHINERY 

"LIOUOR" 

"SILVFR" 

"SP ICES" 

"ELECTRONIC PAR 

"MECHANICAL PAR 

"CYBERNETIC PAR 

"COMPUTER PARTS 

•MACMINF TOOLS" 

"SPACE SUITS" 

"FRUIT" 

"TEXTILES* 

"POLYMERS" 

•MEAT" 

"PETROCHEMICALS 

■GRAIN" 

"WOOD" 

"COPPER" 

"TIN" 

"STEEL" 

"ALUMINUM" 

TAR OATA 

2. 83, -7. 36, 20 

-2.4,-3.56,9 

8.16,9.93,2 

-6.1,0,24 

0,0,12 

-6.87,2.05,5 

6.45,6.65,18 

2.99,7.42,1 

•4.43,9.3,22 

-.89,10.26,10 

ARGO DATA 

3, -2, 2, -2,0, -4, 

0,1,4,-1,0,-2,1 

•2,0, -4, 6,1, -2, 

•>»«*»"A»5»"2»0« 

«,•■>, 4, -4, -1,1, 

•2.4.-1.3. 1,-1, 

2,0,«1, 1,0,0,6. 

1 ,0, -2,0,0,0, 1 . 



TS" 
TS" 

TS" 



20000,1 
,0O000E»06,l 
200000. ,1 

100000. ,1 

1.00000E*06.1 

1.00000E-06.1 

0O000E»06,l 

00000E«07,1 




Fast, reliable delivery 
of personal computer 
software programs. 

If you have an Apple or TRS-80 
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hundreds of programs — in stock 
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5422 Fisher St. White Bear Lake. MN 55110 

Apple » a registered trademark of Apple Computers TRS-Htl is a registered trademark of Radio Shack. A Tandy Corp. 
CIRCLE 166 ON READER SERVICE CARD 142 



4330 
4340 
4350 
4360 
U170 
4380 
4390 
4400 
4410 
4420 
4430 
4440 
4450 
4460 
4470 
4460 
4490 
4500 
4510 
4520 
4530 
4540 
4550 
4560 
4570 
4580 
4590 
4600 
4610 
4620 

4630 



DATA -2,2 

DATA 0,2, 



OATA 
OATA 



•2,6 
•1,6 



OATA -1,3 
OATA -4,7 



OATA 
OATA 



•3,6 
•2.2 



OATA 3,3, 
OATA 3,-1 
OATA 4,»2 
DATA 0,0, 
OATA 0,1, 
DATA 1,0, 
DATA -1,0 
OATA 1,0. 
OATA -1,2 
OATA 1,2. 



DATA 

OATA 
DATA 



3,0, 
•2.0 
0,0. 



DATA 2,0. 
DATA 0,0. 
OATA 0,0, 
DATA 2,2, 
OATA 2,2, 
DATA -1,2 
DATA -1,1 
REM PRICE 
DATA .4,. 
1.2.1.3.1 
END 



•2.1.1.0 

2.0,0.1. 

•4,1,0,0 

•5,2,0,0 

•2,0,0,0 

-8,4,5,0 

•4,1,0,0 

-6.O.6.- 

1,0,-3,0 

3,-1,0,- 

3,»l,-5, 

4,4,1,1, 

3,3,2,1, 

4,2,1,0, 

-2.3,0,0 

2,1,0,0 

•3,2.2,0 

,1,-4,-6 

3,1,-5.- 

3,3,0,0, 

.2.-5,5, 

,-2.3,0, 

.3,-5,6, 

.2.-7,3. 

,•2.-1.- 

.•4,»1 ,• 

6,0,0,0, 

3,«2»0,» 

DATA 

,.7. .6.. 

5.1.7.2, 



, 300000. ,1 

700000.,! 

,30000,2 

,30000,2 

,200000. ,2 

.10000,2 

,50000. ,2 

4, 150000. ,1 

,10000,1 

2, 70000. ,1 

2,6000,1 

100000. ,1 

75000. ,1 

250000.. 1 

, 150000. .1 

750000.,! 

,400000., 1 

,1000,2 

3,3000.3 

7000.4 

1500,4 

10000,6 

300,8 

1000,2 

4,2000,2 

2,9000,3 

500,4 

2.1000.5 

9.1,1.1, 
3.4 



"// you tell a man there are 300 billion 
stars in the universe, he'll believe you. 
But it you tell him a bench has just been 
painted, he has to touch it to be sure. " 

Anonymous 



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Most items a stoth lor immediate deter? factory sealed cartons 
* t u ii tjctom warranty NTS restfents add appropriate sales tai 
Prices do not .nciuo shippr* VISA and Master Ctoffr add i\ 
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CIRCLE 1 30 ON READER SERVICE CARD 



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Ivan Smith 



Nuclear power plants are going to be 
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clear idea how they work. 

A written description of something as 
complex as a nuclear power plant has a 
tendency to overwhelm people with lay- 
ers of detail. There is no way to write a 
description of the interactions between 
the rate of heat generation in the reactor 
core, the rate of flow of primary and sec- 
ondary coolants, the electrical power out- 
put of the turbine-generator, and the tem- 
peratures of the various components, and 
at the same time have a readable, compre- 
hensible, reasonably accurate presenta- 
tion which is interesting enough for most 
people to wade through. Here is an oppor- 
tunity for microcomputers to show their 
stuff. 

Simulation is a field in which micro- 
computers can make a major contribution 
toward a better-informed population. 
Computers certainly have a bright future 
in such applications as information retrie- 
val and record-keeping, but their educa- 
tional potential has not even begun to be 
developed, especially in the public 
schools. The ability of a computer to sim- 
ulate a complex and fluid situation, and to 
involve a person directly in that situation, 
cannot be duplicated or even approxi- 
mated by books, films, television, or by a 
human teacher— no matter how gifted. 

For these reasons I was glad to find 
Stephen R. Berggren's nuclear power 
plant simulation program in the Decem- 
ber 1980 issue of Creative Computing. 
This is a fine example of the sort of simula- 
tion which develops the unique educa- 
tional capabilities of microcomputers. It 
tackles a topic which is vitally important 
to today's society, a topic which has been 
almost totally ignored in the public 
schools. Sure, the schools talk about radi- 
ation hazards from an environmental 



Ivan C. Smith, P.O. Box 226. Chester. N.S.. 
Canada BO) 1J0. 




point of view, an important subject, but 
how many of this year's high school gradu- 
ates will have even a foggy notion of how a 
nuclear power station works'! For that 
matter, how many teachers— even sci- 
ence teachers— know? 

Berggren's simulation makes it easy, 
even entertaining, to find out the basics of 
the inner workings of the heat cycle of a 
nuclear power plant. 

The school in which I work has PET 
computers. Berggren's program is written 
for the Apple, so I undertook to adapt it 
for the PET. I found it took more effort to 
make this adaptation than I expected. 
Here is the result, so that this valuable 
simulation will be available to many who 
might want to use it, but do not have an 
Apple. 

To maintain as much comparability as 



possible between this PET version and the 
original Apple version, the statements 
have not been renumbered, despite a cer- 
tain higgledy-piggledy quality which has 
evolved. I have not tampered with the 
core of Berggren's program, the equations 
which describe the heat transfer charac- 
teristics of the plant, because they work 
very well as they are, and because I do not 
understand them well enough to attempt 
any changes. 

The graphics, which begin at statement 
6000, have been completely rewritten by 
my son, Hume Smith. Berggren's com- 
mentary on variables, which begins at 
statement 9000. is reproduced in Figure 1. 
His variables have been retained without 
change except as noted below. 

New variables VE and VE$, statements 
762-766, have been introduced to repre- 



Figure 1. 



9O0O 
9010 



9020 
9830 

9040 

9050 
9060 
9070 
9880 
9090 
9100 
9118 
9120 
9138 
9140 
9150 
9160 
9170 
9180 
9190 
9200 
9210 



REM UARIABLE PREFIXES 

REM A-CONTROL RODS- C-COOLING TOWER, E-EMERGENCV COOLANT- 
G-TURBINE. P-PRIMHRV COOLANT- R-REHCTOR- S-SEC0NDAR7 COOLANT, 
X-HEAT EXCHANGER 
REM UARIABLE SUFFIXES 

REM B-BROKEN. D-DAMAGE, F-FLOW RATE- H-HEAT FLOW- L -LIFE, O-OUTPUT- 
T-TEMPERATURE- U-UOLUME 

REM OTHER UARIABLES TOT-TOTAL POWER OUTPUT- KW-HUERAGE POWER 
OUTPUT- DAV-DAV OF OPERATION, DMGE-TOTAL EQUIPMENT DAMAGE 
REM PROGRAM DISCRIPTION BV LINE NUMBER 
REM 10-220 INTRODUCTION 
REM 225-388 INSTRUCTIONS 
REM 390-455 UARIABLE INITIATION 
REM 460-850 WRITE REPORT AND ASSESS DAMAGE 
REM 900-1165 INPUT NEW CONTROL UARIABLES 
REM 1170 MAINTENANCE SHUTDOWN EVALUATION 
REM 1200-1260 PUMP FAILURE ASSESSMENT 
REM 1270-1430 PLANT OPERATING ALGORITHMS 
REM 2000-2200 MAINTENANCE SHUTDOWN SUBROUTINE 
REM 3000-3190 MELTDOWN ENDING 
REM 4000-4290 EVALUATION OF GAME RESULTS 
REM 5800-5070 END 

REM 6000-7<?i6O PLANT DIAGRAM SUBROUTINE 
REM 9000-9190 REMARKS 
REM APPLE NUCLEAR POWER PLANT 
REM BY STEPHEN R BERGGREN 



144 



CREATIVE COMPUTING 



80 COLUMN GRAPHICS 



The image on the screen was created 
by the program below 



10 VISMEM: CLEAR 

20 P-160: Q-100 

30 XP=144: XR-1. 5*3. 1415927 

40 YP-56: YR-1: ZP»64 

50 XF«XR/XP: YF=YP/YR: ZF=XR/ZP 

$0 FOR ZI»-Q TO Q-l 

70 IF Zl<-ZP OR ZI>ZP GOTO 150 

80 ZT»ZI*XP/ZP: ZZ»ZI 

90 XL-INT (. 5+SQR (XP*XP-ZT*ZT) ) 
100 FOR XI—XL TO XL 
110 XT-SQR(XI*XI+ZT*ZT)*XF: XX-XI 
120 YY«(SIN(XT)+.4*SIN(3*XT))*YF 
130 GOSUB 170 
140 NEXT XI 
150 NEXT ZI 
160 STOP 
170 X1»XX+ZZ+P 
180 Yl-YY-ZZ+Q 

190 GHODE 1: MOVE XI, Yl: WRPIX 
200 IF Y1»0 GOTO 220 
210 GMODE 2: LINE X1,Y1-1,X1,0 
220 RETURN 



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Power Plant, continued... 



sent the dollar value of the energy pro- 
duced. This has been calculated at 5.5C 
per kWh, a value which can be changed in 
statement 762. VE$ is used to convert a 
number greater than 9999 to a format easy 
to read, with the digits grouped by threes. 
This grouping has traditionally been done 
by using a comma , but is done here using a 
space as is the style in metric usage. Users 
who may wish to use the traditional for- 
mat with a comma between the thousands 
and ten-thousands digits, can alter the 
concatenation in statement 766 by insert- 
ing +","+ in place of +"" + . 

In the original program, commentary 
statement 9040 assigns TOT to represent 
the total energy output, but the operating 
variable appears to be TT, as in state- 
ments 765 and 1420. Variable BL$, used in 
the PET version in statements 40, 920, 
960, 1000, 1 120, etc, consists of 36 spaces 
followed by cursor home, and is used to 
clear one line on the screen. 

In the original program, statements 
1210 and 1220 are used to generate a ran- 
dom damage factor for the primary and 
secondary coolant loops. There is a 5% 
change of primary loop damage whenever 
the primary coolant flow exceeds 90%, 
and an 8% chance of secondary loop dam- 
age whenever the secondary coolant flow 
exceeds 90%. This damage shows up as a 
leakage rate, which is simply a count of 
the number of times the random factor 
occurs. The leakage accumulates in each 
coolant system, and a shutdown is forced 
when leakage reaches 5 in either system. 
In running this program many times, I 
got the feeling that each run was much the 
same as every other run, and that the 
leakage factor was a bit too simple. All 
one had to do was keep the coolant flows 
below 90% and everything would go well 
almost indefinitely. I decided to alter the 
random leakage factors to a more inter- 
esting and a more realistic format, using 
three ideas: quality of workmanship, 
multi-step flow-dependent random dam- 
age, and age-dependent random damage. 
First, a construction or repair job can 
be performed well or poorly. Two new 
variables were introduced, QP% and 
OS%, representing the quality of the 
materials and workmanship in the pri- 
mary and secondary coolant loops. These 
variables are set equal to 1 to represent 
first-rate quality, to 2 to represent second- 
rate, and to 3 to represent third-rate. The 
values of QP% and QS% are selected inde- 
pendently of each other, to reflect the fact 
that sometimes one job is done well while 
the other is not. In running the simulation, 
this means that a leakage shutdown will 
sometimes be due to primary leakage, 
sometimes to secondary trouble. The val- 
ues of QP% and QS% are defined on 
startup at statements 430 and 440, and 
redefined at 2020 and 2030 after a main- 
tenance shutdown. 



In selecting the values of QP% and 
QS%, a probability of 0.57, the square root 
of 0.33, is used as the threshold between 
first-rate and inferior quality. This means 
that one startup between first-rate and 
inferior coolant systems is first-class con- 
dition. The remaining startups will occur 
with one or both coolant systems 
impaired. As the simulation runs, QP% 
and QS% are used at statements 1210 and 
1 220 to select different damage probabili- 
ties for each coolant system. 

Second, a three-step flow-dependent 
random damage factor has been intro- 
duced. Let's use statements 121 1 and 1212 
as an example. These statements define 
the probability of a leak occurring in the 
primary coolant system when the work- 
manship is of first-class quality. When the 
primary coolant flow PF% is greater than 
65, there is 1 chance in 5000 of a leak 
occurring on any given day of operation. 
When the flow rate exceeds 90 the proba- 
bility of a leak increases to 1 in 250, and it 
reaches 1 in 20 when the flow exceeds 95. 
With lower-quality workmanship, the 
flow thresholds are reduced and the dam- 
age probabilities are increased. In the pri- 



This represents a 

sneaky pedagogical 

trick, Introducing the 

Idea of a rate of change 

In a situation where It Is 

vitally useful. 



mary coolant system the flow thresholds 
are slightly lower than in the secondary 
system, but the probabilites of leakage are 
slightly less. 

Third, a plant aging factor has been 
inserted, which slowly increases the prob- 
ability of a leak occurring in either cooling 
system as the plant accumulates operating 
days. These aging factors are the last 
terms in statements 1212, 1214, 1216, 
1222, 1224, and 1226. The aging factors 
for poorer-quality systems have higher 
probabilities of leakage. 

My statements 1210 to 1226 can be 
removed and the original statements 1210 
and 1220 can be reinstated, and the PET 
simulation will continue to operate prop- 
erly. Alternatively, users can rewrite 
these statements to suit their own ideas 
about these leakage probabilities. 

GO% was used as a variable in the origi- 
nal program, for example in line 1380. 
Unfortunately, this is an illegal variable in 
the PET. It has been replaced with GZ%, 
representing turbine-generator power 
output. 

146 



As Berggren noted in his documenta- 
tion, this program "makes extensive use of 
logic evaluations within expressions. For 
example, (A > 100) equals one if true and 
zero if false." The PET handles such logic 
expressions, but returns a negative one if 
true, and zero if false. This means that all 
logical expressions must have their signs 
changed, in translating from Apple to 
PET Basic. To see the effect of this, com- 
pare statements 1212, 1214, etc. At first 
glance it would appear that these aging 
factors operate to reduce leakage, since 
they are subtracted. But the effect is addi- 
tive, because we are subtracting a nega- 
tive value. 

In the PET version, time delays have 
been added to slow down the rate at which 
text is thrown on the screen. The time- 
delay subroutine starts at line 5300, and 
uses variable Z4 to control the time delay. 
Z4 is calibrated roughly in tenths of a 
second. In line 48 for instance, Z4 is set 
equal to 8. This means the next delay will 
be about 8 tenths of a second. Z4 is auto- 
matically incremented by 3 each time the 
delay routine is used. This has the effect 
of starting down the screen fairly quickly, 
then gradually slowing down as the screen 
fills. The delays can be adjusted by chang- 
ing the Z4 coefficient in line 5300. Coeffi- 
cients greater than 63 will increase the 
delays, less then 63 will reduce them. To 
prevent insanity during debugging, it is 
recommended that the 63 be reduced to 
about 6. When everything is running, 
restore it to a suitable value. 

After this simulation run is completed, 
that is, when the fuel charge has been 
exhausted, the program offers a comment 
on the operator's competence. The com- 
ment is selected by calculations per- 
formed in line 4050 in the Apple version, 
or in lines 4020-4022 in the PET version. 
Additional comments have been added to 
the PET version, and the thresholds have 
been lowered, to give a bit more encour- 
agement to the beginner. Operation at a 
load factor of 60% is considered to be 
acceptable, and a load factor of 70% is 
considered good. I believe these interpre- 
tations are not substantially different 
from those prevailing in the industry. 

Finally, the screen display of operating 
information presented difficulties in com- 
pleting the adaptation. While the Apple 
instructions VTAB and HTAB were easy 
to interpret, I couldn't figure out what 
CALL-958 or CALL-922 (lines 1 165 and 
1170) might mean. To get around this, I 
did a complete rewrite on this program. I 
can't venture an opinion whether my ver- 
sion is better or worse than the original, 
because I have no idea how the original 
works. However, I added a couple of fea- 
tures which I believe are not present in the 
Apple version. The PET version gives the 
equipment temperatures as does the 
Apple version, but in addition the PET 

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CIRCLE 231 ON READER SERVICE CARD 



AUGUST 1981 



147 



Power Plant, continued... 



gives the change from the previous read- 
out. This is of considerable help to the 
operator. The operating response to a 
reactor core temperature of 740 degrees 
will be different, depending on whether 
this represents a decrease of 5 degrees, an 
increase of 5 degrees, or an increase of 50 
degrees compared to the previous tem- 
perature. This also represents a sneaky 
pedagogical trick, introducing the idea of 
a rate of change in a situation where it is 
vitally useful, in an attempt to foster a 
better understanding of the general signi- 
ficance of rates. 

Another innovation (at least I think it is 
an innovation) is the continuous reporting 
of the leakage rates, regardless of whether 
they are serious enough to require shut- 
down. This enables the operator to judge 
more clearly how events are developing, 
and adds some dramatic suspense: "The 
blasted secondary leakage is up to 4 
L/day, and I've just got the plant settled 
down at 1820 kW. How long can I con- 
tinue?" Leakages have been given the 
physical unit of litres per day. 

I have suppressed the "low power out- 
put" warning during the first eight days 
after a startup, to give the operator a fight- 
ing chance to get the plant under way. 
This suppression is performed in line 464, 
and uses variable D4% to identify the 
startup day. 

In this version, the trouble warnings are 
presented on the screen in a frame sepa- 
rate from the operating conditions frame. 
Statement 472 suppresses the warning 
frame if no warnings are to be displayed, 
while lines 462-470 decide whether to 
override the suppression. The warning 
frame presents both warnings of out-of- 
range operating conditions and reports of 
damaged equipment. Variable SW is used 
to state "None" if this frame is activated 
but there is either no warning or no 
reportable damage. In the Apple version, 
line 4040 uses the phrase "kilowatts per 
day," and 770 contains a similar phrase. 
These have been corrected. 

When an operating readout comes up 
on the screen, the program asks for four 
control settings, in turn: control rods, 
emergency coolant flow, primary coolant 
flow, and secondary coolant flow. If the 
current value of any of these is to remain 
unchanged, press the up-arrow " ! " with- 
out putting in a number. If all values are to 
remain unchanged, press 1 four times. If 
a value is to be changed, type in the new 
value, terminated by ' . The input routine 
will automatically terminate each entry if 
three digits are input. As in Berggren's 
program, these variables are each set to a 
value from to 100. 

The Control setting input routine, state- 
ments 10-15, does not include a delete 
feature. This omission is deliberate, to 
reflect the "unforgiving" nature of 



NUCLEAR POWER PLANT SIMULATION 
FOR PET COMPUTER 



POKE 167,0 



-I I _-/" : Z4=7 GOSUB5306 



REM 
1 

2 REM 

3 i 

4 REM BV I VAN SMITH * HUME SMITH 
5 

6 REM BRSED ON S. R. BERGGREN, CREATIVE COMPUTING DECEMBER 1980 PAGE 128 FF 

7 ■ 

8 REM REVISED 23 DECEMBER 1980 

9 G0T048 

10 POKE158,0B*="" PRINT" 

11 GETA» IFA*=""THEN11 

12 Z=ASC<A*>IFZ=94THEN15 

13 IFZ<480RZ>57THEN11 

14 PR I NT A*; :B*=B*+A*:IFLEN(B*K3THEN11 

15 P0KE167, 1: PRINT" "^RETURN 

40 P0KE59468, 14R=RND(-TI) BL*=" 

41 Tl*=" T\ /r\Tt- TO - - T.*/l " 

42 T2*="M «l*l * -~T-\ , -* I" 
44 PRINT"^B U T1*PRINTSPC<7'"WBV 9l~ IrV— I" 
46 PRINTSPC(5>"WBRS MODIFIED BV THE STAFF OF" 

48 PRINT"M l_-,-| - 0*l~_ Kl I •- im_, A~X* »Th»" : GOSUB5300 : Z4=8 
50 PRINT"M«MIHIS PROGRAM SIMULATES THE OPERATION OF" 
60 PRINT"MA NUCLEAR POWER REACTOR. ■; GOSUB5308PRINT" I HE OBJECT" 
70 PR I NT "MIS TO OPERATE THE PLANT AT AS HIGH A" 

80 PRINT"M= , 0WER OUTPUT AS POSSIBLE"; GOSUB53O0 PRINT", WITHOUT" 

90 PR I NT "CAUSING A REACTOR MELTDOWN. ■ G08UB9366 

92 F0RZ5=1T07 PRINTTABC 18 > 'HSWELTBOWN!" F0RZ6=1T050 NEXTZ6 

94 PRINTTAB<18>"'T1ELTD0WN" FORZ6=1TO50 NEXTZ6,Z5GOSUB5310 

100 PRINT'TTO V0U WANT INSTRUCTIONS"; INPUTZ*: IFZ*="N"THEN350 

102 IFZ*O"V"THEN100 

110 PRINT'TJIHE CONTROL PODS" ADJUST THE AMOUNT OF" 

120 PRINT"«HEAT PRODUCED BV THE REACTOR." Z4=l 1 GOSUB5308 

130 PRIHT'NHE 5PRIMAPV COOLANT" TRANSFERS THIS" 

140 PRINVXHEAT TO THE HEAT EXCHANGER." G0SUD9380 

142 PRINT"MWIHE ^SECONDARY COOLANT? PICKS UP HEAT" 

144 PRINT"MFR0M THE HEAT EXCHANGER", GOSUB5300 PRINT" , AND TRANSFERS" 

150 PRINTMWIT TO THE 3TTURBINE"" ; GOSU853O0 PRINT" . WHICH DRIVES" 

160 PRINT"WTHE ELECTRIC GENERATOR. »: ■ GOSUB5300 PRINT" I HE SECOHDARV" 

170 PRINT"MC00LANT THEN GOES TO THE COOLING TOWERS- " GOSUB5300 

172 PRINT "HAND THEN BACK TO THE HEAT EXCHANGER. ":GOSUB93Oe:GOSU89310 

180 PRINT"7}IHE 5EMERGENCV COOLANT" IS USED TO HELP" 

132 PRINT"*3HUT DOWN THE REACTOR"; 24=11 GOSUB5300: PRINT" WHEN OTHER SVSTEMS" 

184 PRINT"FAIL." GOSUB53O0 PRINT"MlUJLIKE THE OTHER COOLANTS," 

186 PRINT"MEMERGENCV COOLANT IS NOT RECYCLED. " = 0081189380 

188 PRINT"MIHIS MEANS V0UR SUPPLV OF EMERGENCY" 

190 PRINT"MC00LANT IS LIMITED. " G0SUB5380 : GOSUB5^10 Z4=13 

192 PRINT'THN INCREASED FLOW OF PRIMARY COOLANT" 

194 PRINT"MWILL LOWER THE REACTOR CORE TEMPERATURE" GOSIIB5300 

196 PR I NT" BAND WILL RAISE THE HEAT EXCHANGER" 

198 PRINT"MTEMPERATURE. ": 608088300 

200 PRINT"«M*N INCREASED FLOW OF SECONDARY COOLANT" 

262 PRINT"JMLL LOWER THE HEAT EXCHANGER" PRINT"WTEMPERATURE" : GOSUB5380 

204 PRINT", AND WILL INCREASE THE" PRINT"BP0WER GENERATED", GOSUB5300 

206 PRINT", BUT WILL RAISE THE" 

208 PRINT"WC00LING TOWER TEMPERATURE." GOSUB5300 GOSUB5310 Z4=13 

210 PPINT'TJfUCCESSFUL OPERATION DEPENDS ON" 

212 PRINT"«GETTING A BALANCE": : 008089306 

214 PRINT", BETWEEN THE" PRINT"MHIGH TEMPERATURES NEEDED FOR" 

216 PRINT"WPOWER GENERATION", GOSUB53O0 PRINT" AND THE" 

218 PRINT"MTEMPERATURE LIMITS OF THE MACHINERY. " 008069300 G0SUB53 10 

220 PRINT"rHWWTNTER - TO SEE REACTOR DIAGRAM." 

222 PRINT"*TNTER % FOR WORKING INSTRUCTIONS." 

224 PRINT"WXTER • TO START OPERATION." 

226 PRINT"M"TAB<13>; : INPUTA* ■ IFA*="D"THENGOSUBf r .OOO ■ AOT0220 

227 IFA«="S"THEN390 

228 IFA*<>"I"THEN226 

230 PRINT'^IHE CONTROLS ARE OPERATED BV TYPING IN" 

235 PRINT"WTHE DESIRED CONTROL ROD SETTING", Z4=13GOSUB5300 PRINT" AND" 

240 PRINT"MFLOW RATES. " GOSUB5306 PRINT"WW,SE VALUES FROM TO 100. "; = 008089306 

242 PRINT" -,F NO ENTRY" PRINT'MIS MADE, THE PREVIOUS SETTINGS WILL 

244 PRINT"M=:EMAIN UNCHANGED. " GO8UB9306 

250 PRINT"M«^E "CHR*<34>" t"CHR*<34)" TO STEP TO THE DIFFERENT" 

255 PRINT")(FUNCTIONS. ", GOSUB5300 PRINT" OHEN THE DESIRED" 

260 PRIHT"BENTRIES HAVE BEEN MADE, THE" PPINT"»(EXT DAY S CONDITIONS"; 

265 PR I NT " WILL BE " PR I NT " MCALCUL ATED . " G0SUD9366 G0SUB53 1 

270 PRINT-HIHE REACTOR CAN BE KEPT OPERATING UNTIL" 

272 PRINT"MTHE REACTOR FUEL IS EXHAUSTED"; =Z4-1 3 :008U89300 :PRINT" , OR" 

274 PRINT"MJNTIL A MELTDOWN OCCURS. ": 00SUB9306 

276 F0RZ5=1T07PRINTTAB<8>'H*1ELTD0WNB" FORZ6=1TO50 NEXTZ6 

278 PR I NTTAB < 8 ) " T1ELTD0WN " F0RZ6- 1 T090 NEXTZ6 • ZS 

280 PRINT"MSIHE FUEL WILL LAST ABOUT 100 TO 150" 

282 PRINT")flDAYS"; GOSUB530O PRINT", DEPENDING ON HOW MUCH" 



148 



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ders • Dot resolution graphics • Bi- 
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CPS • RS 232 Serial 4 Parallel • Forms 
control • X-ON/X-OFF • Up to 6 part 
copy. 



ANADEX 9501 (List $1650) $1350 




AXIOM 




Dot Graphics, Low Price 



• Dot addressable graphics • 70 CPS 

• 12 characters per inch • 80 columns 

• adjustable tractors • 3 part copies 

• Manufactured by Sieko • Parallel. 
RS232 serial. IEEE 488 interfaces 
available. 



AXIOM GP-80M (List $399) $349 

IDS PAPER TIGERS 

Dot Resolution Graphics, quality print, speed 



• 7 wire printhead (445); 9 wire printhead 
(460) with lower case descenders • Over 
150 CPS • bi-directional, logic seeking 
(460) • 8 character sizes; 80-132 columns 

• Adjustable tractors • High-resolution dot 
graphics • Proportional spacing & text 
justification (460). 

IDS 445G 7 wire printhead. graphics (List $895) $ 750 

IDS 460G 9 wire printhead, graphics (List $1394) $1150 

IDS 5600 9 wire, wide carriage, graphics (List $1794) $1400 A 





EPSON MX80/MX70 



Low-Priced 
Professional Print Quality 

• 9 x 9 dot matrix • Lower case descenders 

• 80 CPS * Bidirectional, Logic seeking • 
40, 66, 80, 132 columns per line • 64 special 
graphic characters: TRS-80 Compatible • 
Forms handling • Multi-pass printing • Ad- 
justable tractors 

We also carry a lull line 
of Epson Accessories. 

EPSON MX80 (List $645) $Call 

EPSON MX 70 Dot graphics, 5x7 matrix (List $450) $Call 

EPSON MX100 wide carriage (List $995) JCall 

QRAPPLER™ Apple graphics parallel 

interface and cable $ 165 

MX80/70 FRICTION FEED KIT 

Uses installable kit for single sheets. 

Easy 15 minute installation. $ 75 



ANACOM 

Low Cost, High Speed, Wide Carriage 

• 9 x 9 dot matrix • Lower case descenders • Wide carriage • 
Adjustable tractors to 16" • 150 CPS, Bidirectional, Logic Seeking 

ANACOM 150 (List $1 350) $ Call 

NEC SPINWRITER 

High Speed Letter Quality 

• 55 CPS • Typewriter quality • Bidirectional • Plotting • pro- 
portional spacing. 

5510-5 RO, Serial, w/tractors (List $2995) $2675 

5530-5 RO, Parallel, w/tractors (List $2970) $2650 




TELEVIDEO CRT'S] 

AT DISCOUNT PRICES! 



QUANTITY PRICING AVAILABLE 



TVI 910 
TVI912C 
TVI 920C 
TVI 950 



} 



Please Call Toll Free 
Prices are too low to 
advertise 



PRINTERS 

MALIBU 165 wide carriage, graphics, letter quality (List $2495) $1975 
QUME 5745 typewriter quality (List $2905) $ 2559 

VISTA-C. ITOH Starwriter, letter quality (List $1895) $ Call 

INTERFACE EQUIPMENT 

I EPSON ACCESSORIES $ Call 

| ORANGE INTERFACE for Apple II 

parallel interface board & cable $ 110 

I MICROTRONICS Atari parallel interlace $ 69 I 

I TRS-80 CABLES to keyboard or Exp interlace * Call 

NOVATION D CAT direct connect modem $ Call 



CALL FOR FREE CATALOG 

(800) 854-8275 

CA,AK, HI (714) 630-3322 

At Orange Micro, we try to lit the right printer to your application. 
Call our printer specialists lor tree consultation. 



RETAIL PRINTER STORES: 

3150 E. La Raima. #l, Anaheim, CA 

13604 Ventura Bl . Sherman Oaks. CA 

Store Hours: M F 10 6 Sat 10-4 




Phone orders WELCOME; same 
day shipment. Free use of VISA & 
MASTERCARD. Personal checks 
require 2 weeks to clear. Manu- 
facturer's warranty included on all 
equipment. Prices subject to 
revision. 



Oronge 

iTllCrO, Inc. 

3150 E. La Palma. Suite I 
Anaheim. CA 92806 



CIRCLE 250 ON READER SERVICE CARD 



Power Plant, continued... 



nuclear technology. If an operating error 
is made, its consequences must be 
endured, at least for one operating cycle. 
If an operator types 80 for a control rod 
setting when 8 was intended, the compu- 
ter will give a vivid illustration of the con- 
sequences of such an error, and the opera- 
tor will learn a few things as he tries to 
salvage the plant in subsequent cycles. I 
have made such errors, and have found 
the results to be "interesting." If a user 
wishes to include a delete feature, the 
input routine should be replaced by the 
following: 

10 Same as existing 10 

1 1 Same as existing 1 1 

12 Z=ASC(AS):IFZ=94THEN17 

13 IFZ=20ANDLEN(B$)=1THENB$ 
="":?CHR$(20);:GOTOll:REM 
DELETE 

14 IFZ=20ANDLEN(B$)=2THENB$ 
=LEFTS(B$,1):?CHRS<20);: 
GOTO 11 

15 Same as existing 13 

16 Same as existing 14 

17 Same as existing 15 

In watching students run the program, 
it was noted that the ' would sometimes 
be pressed five or six times, once or twice 
more that the required four. The extra 
characters remained in the keyboard 
input buffer, and caused the program to 
skip over the first one or two control 
inputs on the next cycle, which created 
unnecessary difficulties. To eliminate 
this, POKE 158,0 was inserted in line 10. 
This sets the keyboard input buffer 
counter to zero at the start of each input, 
eliminating any spurious characters which 
might be lurking in the buffer. The POKE 
167,0 in line 10 turns the cursor on, while 
the POKE 167,1 in line 15 turns it off. 

The POKE 216 used in lines 920, 930, 
5310, etc., positions the cursor on a screen 
line. POKE 216,n:? positions the cursor 
on line n+2. For example, POKE 216,17:? 
places the cursor on line 19 for the next 
print. The POKE 216,n must be followed 
by a blind PRINT instruction, otherwise it 
won't take effect. 

The PET nuclear plant simulation 
occupies 14. IK of memory, and presum- 
able will work in a 16K machine. I used a 
32K PET model 2001-32N. 

Berggren claimed his program "is 
almost entirely crashproof." a statement 
which drew the rejoinder "famous last 
words." I have seen this program run more 
than fifty times by a variety of inexperi- 
enced operators, and have yet to see a 
crash. Berggren's claim seems to be justi- 
fied. 

I think Berggren's simulation is the 
most useful education program ever pub- 
lished by Creative Computing. It can form 
a foundation for variations which simulate 
other reactor types, or which go into 
greater detail, and it may serve as inspira- 
tion for other simulations. n 



284 
290 
295 

300 

305 
310 
3J5 

320 
325 
330 
335 
340 
358 
355 

36e 

362 
3-54 
366 
370 
390 

400 

410 
420 
430 
440 
442 
444 
450 
455 
460 
462 
464 
466 
468 
479 
472 
480 
490 

500 

510 
512 
514 

520 
522 
524 
530 
532 
534 
540 
55G 
560 
570 
580 
590 
660 
610 
620 
630 
632 
634 
640 
642 
644 
650 
652 
654 
660 
662 
664 
670 
672 
674 
630 
690 
692 
694 
696 
700 
71© 
720 
722 
724 
730 
732 
734 
740 
742 



PRINT"MENERGV IS PRODUCED EACH DAY. " GOSUB5300 

PRINT"H»oHEN THE FUEL IS EXHAUSTED, TOUR" 

PR I NT " (PERFORMANCE WILL BE SUMMARIZED." 008109366 :Q0SUD93 10 

PRINT"3%F V0U WANT TO REPAIR DAMAGE OP REPLACE" PR INT" WOOL ANT" ; 24=1 1 

GOSUB5380 PRINT", BRING THE REACTOR TEMPERATURE" 

PRINT"HDOWN BELOW 100" ; 6OSUBS360 PRINT" . AND SHUT OFF THE" 

PRINT"J!>:00LAHT FLOWS.". GOSUB5300 PRINT" I HIS WILL CAUSE" 

PRINT'MRN AUTOMATIC MAINTENANCE SHUTDOWN. " GOSUB5300 

PRINT"M_EPAIRS WILL BE MADE"; GOSUB5360 PRINT" , AND ALL COOLANT" 

PRINT'ttJILL BE REPLENISHED. " QOSUB5300 

PR I NT "MM HE GREATER THE DAMAGE- THE LONGER" 

PRINT"MTHE REPAIRS WILL TAKE. " GOSUB530O GOSUB5310 

PRINT"r3"TAB<lS)"«««««3:i*- ,-, I " 

PRINTTAB<7 VMM K» To"- ~I_* I !*•" 

PR I NTTAB ( 3 > " WMT ♦ ,1 l"\* I % - ♦*-"! I — x-, -~# ! ! " : 24= 1 3 : GOSUB5300 

PRINT"MMM HE OPERATOR" , 24=4 GOSUB530O PRINT" , < YOU) " , : GOSUB5308 

PRINT", IS RESPONSIBLE" 

PRINT-M^OR SAFE OPERATION OF ALL EQUIPMENT." 

GOSUB5300 G0SUB53 1 GOTO220 

REM INITIATE 

oosuseeee 

RH=0 RL=0 : TT=0 

dav::=o D4::=u 

eP*.'=l-CRND<2».57)-<PND(2)>.95) 

QS;;=1-<RND<2».57>-<RNDC2».95> 

rem qp::=qualitv OF PRIMARY LOOP WORKMANSHIP, QSJ<=SAME FOR SECONDARY LOOP 

REM 1 FOR FIRST-CLASS WORK, 2 FOR SECOND-CLASS, 3 FOR THIRD-CLASS 

DMGEX=0 

AX=0 A1'.'=0 f\2X=V> 

DAVX=DAV?i+l PRINT":)", REM WRITE REPORT 

IFRT?i>800ORXT?i:>500ORCT':>300ORG2/:>2000THEN480 

i fgz>:< 1 000AND < day::-D4-:>s • then4so 

IFEV?i<200ORPV^< 1 00ORSVX< 1 00THEN480 

IFRD^:>3ORPD?S>4ORSD^>4ORED*:>2THEN480 

IFPB5i>0ORSBX>0ORXBJi>0ORGBX>0THEN480 

GOTO70O 

PRINTT1* 

printt2*;day:-;"M" 

pr i nt " 0*-/s a • : m" : sw= 1 

IFRT?i<&00THEN520 

PRINT" -EACTOR OVERHEATED" RDX=RD^+l-<RTX>850)-<RTfi>90e>-2*<RT/i>950> 

PD';=PD^+1 -ED^=ED?i+l-(RT/i>850) SW=2 

IFXT/i<500THEN530 

PRINT" EAT EXCHANGER OVERHEATED" 

xdy.=xv/.+i-<xv/.>68Q> PD?s=PDf:+i sv>:-$mt*i sw=2 

IFG2X<2000THEN540 

PRINT" IURBINE OVERLOADED" 

TDr-:=TD:-i+i-<G2?i>2500> sv/.=SDy.+i sw=2 

-OOLING TOWER OVERHEATED" : SD?i=SD?i+l : SW=2 
"EWER OUTPUT LOW" 



SW=2 
"MERGENCV COOLANT L0W"SW=2 
"FIMARV COOLANT LOW" FV/.=PX\'/.+ l ■ SW=2 
•ECONDARV COOLANT LOW" SD?i=SD?i+l SW=2 



SW=2 



I FCT:-i>3O0THENPR I NT " 
I FG2?i< 1 000THENPP I NT 
I FEV;;<200THENPR I NT " 
IFPV5X100THENPPINT" 
I FSV*i< 1 OOTHENPR I NT " 
ONSWGOTO600.610 
PRINTTAB<ll>"/ONE" 
PRINT"«-*\f|- M" SM-1 

ifpd::>3Thenprint"rea«tor core damaged 

ifpdx<5then640 

pr i nt ""pi mary coolant leak " , pdk, "lv'dav" 

pvx=<pvx-pd;<>*<-< <pv?i-PD/i>>0> > sw=2 

IFSDX<5THEN650 

PRINT"»EC0NDAPY COOLANT LEAK : " i SDK; "L/DAV" 

sv:;=>sv::-SD?i>*<-<<svji-SDX)>0::'> sw=2 

IFEDXOTHEN660 

PR I NT ""MERGENCV COOLANT LEAK " 2*ED:-i, "UTiAY" 

EV*:=(EV.-:-2*ED?i)*<-<(EV>:-2*ED«)>0)) SW=2 

ifpb^=0then670 

pr i nt ""f' i mary coolant pump failure ", 

pr i nt 1 0*pdx* < - < pd;« 1 > > + 1 00* < - < pdjo- 1 > ) 

ifsb::=0then6SO 

ppint"»ec0ndarv coolant pump failure", 

printi0*sd:>' -> ;rr. :io i >+iee*<-<SDJ£>»l0>) 

IFXB - /.>0THENPRINT" IE AT EXCHANGER FAILURE 

IFGB?O0THENPRINT"I URBINE FAILURE" SW=2 

0HSWG0T0694,696 

PRINTTABdl V/OHE" 

G0SUB53 1 

PRINT'TTTl* PR1NTT2* : DAY5S 

IFRD:05THENPRINT"W fOJ-rO/"!! » ~LI "TO/! 

pp INT" «« miinnn. ^--, -t i r~* •• 

PRINTTABC12VT-ONTR0L ROD POSITION "A'^-fi" 

PRINT"»IEMPERATURES: ■ *♦ -»A~ /To" 

PRINT" -EACTOR 866" 

PR I NTTAB < 25 > " T RTX-T7X PP I NTT AB <: 33 > " T RTX 

T7;.'=RTX 

PRINT" IEAT EXCHANGER 500" 

PRINTTAB(25)"T , XTX-TS^PRINTTAB<33VT , XTJi 



•/." $U=2 



„.... 

1 sw> 



SM-2 



3t\-|_l "TO/! " GOTO3000 



150 



CREATIVE COMPUTING 



2eee> : "gzx-ko" 



744 T8>!=XTX 

750 PRINT" -OOLING TOWER J&U" „ 

752 PRINTTflB«5>"n-CT5i-T9X :PRINTTRB<33>"T"CTK 

760 PRINT"M TOMER OUTPUT <MRX 

762 KWfc>TT/DRV5S-VE=INT<24*TT#.055> ««— «■• 

764 VE*=STR* < VE > ! I F VE< 1 O000THENVE*= " * " +VE* GOTO770 
•?« uc*»»*»+LEFT*<VE«.LEN<VE»)-3)+" "+RIGHT*<VE*,3> 
77B PRINT" "VERHGE POWER OUTPUT "KWX" KO" 

7M PRINT" xfiLUE OF ENERGY PRODUCER »VE* 

906 REM GET NEW CONTROL VALUES 

910 fl2X=fll/i : Rl?i=RX 

I! P^IIl!:!! 'pRiNTPRiNT^NTROL ROD POSITION?"; : GOSUB10 

III SSffi£S'RISS'SffiS»«W«W COOLRHT FLOWr.;:GOSUB.0 

III aB£«K8S-»«iw»«-<«>i^> 

1SSS BSB:Sa8S«BKWn«» coolrnt fuw-^oomm 

.££ fS^SjRffiSiSftfcflWW COOLRNT FLOW ? »; ;6 OSUB 1 

ill ^L^^^^^^KS'skitm-n:-^-^.^ 

1130 FORI = 1TO5000 NEXT I 

1^1 R^^hGe'aIsEsImENT RHD OPERATION CRLCULRTIONS 

!i!~ M>SlMwi/ecvVMMcnilK2».9999>+<PFX>80>*<RHD<2».W»> 

ii!!^:^::sssi > .?:^t!S£gss^i?-' ,5> 

JSg fSr- cT 1 vt^py>6e>*(:RNDC2-».9' : >92> + (SFX>85>«<;RND<i;>^.99> 
1222 !5£!5£ If^>94)* RND «>> 92>-<2400«ND<2><MVJi> G0T01238 
lis auZSttnote" RND 2)> 9985>-KSF»7S>*<RND<2».98> 
liilS^lS^<lF§89>*<RNB<2)>.9>-<1880*RNI.<2><DflV-/.> 

1230 PBJi=-<PItt>5> 

1310 eh=ef^/200*<rt:-:-25> 

1328 RT»RTX*RH-EH-PH-»<-<RT»25» 

;^^sSSisSpS;ie;» + Pv^c-<Pv.<-i«>>>/3 5 0*cxT,-cT ;i > 

1360 IFXB5O0THENSH=SH*.2 

1370 G2?i=SH/XTX«<XT/i-CT5i)*2/3 

1375 IFGZJi>2600THENGZX»2600 

i ^ GZy=GZ«*< - < GZX>6 > > * < " < GB'/.=0 > ) 

Istl CT^=25+*(XTX-25)«<SH-GZ?:)/<SH-H>*.75) 

139S CTX=25#<-<CTX<-25))*CTX*(-<CT«>25>) 

I!m ?FXBp<lTHENXB^=';-<XDJi>2)>«<-<RND<4)>.9)> 

1426 TT»TT*OZX 

2mS REM^WINTENRNCE REPAIR SUBROUTINE 

2010 EVX=300 PV/.= 120SV5i=120 

2020 QP?i=l-<RND<2».57)-<RND(2)>.95> 

2030 QSX=1-<RND<2».57>-CRNTK2».95> 

2040 RT/.=25 : T7'/.=25 

2050 XT?J=25 T8X=25 




RADIO SHACK 

TRS-80® 
Computers 

Buy Direct From re*w*«p- w^ 

Pan American 
Electronics, Inc. 

Discounts • Free Shipping 
TOLL FREE ORDER NUMBER 

» 800/531 -7466 « 



Dept. 27 • 1117 Conway Avenue 

Mission, Texas 78572 

Texas & Principle No. 512-581-2765 

Telex Number 767339 



NEW Showroom/Warehouse 

2912 N. Main • Ft. Worth, Texas 

IPhone (817)625-6333 » Telex 767339 

TM Registered Trademark of Tandy Cwp 



.s 



CIRCLE 186 ON READER SERVICE CARD 



PET/CBM 
PERIPHERALS 



USI YOUR COMMODORI PtT CBM 
ASATERMINAl AISOCONNICT 
TO PRINTERS PLOTTERS TERMINALS 
MODEMS AND TEIEPHONE UNES 

RS-232 OUTPUT ONLY $129 

RS 232 INPUT / OUTPUT $229 
RS-232 DUAL CHANNEL $369 
TELEPHONE MODEM $389 

.AND SOFTWARE TOO!! 



••• 

fROM TNW CORPORATION 

33S1 Hancock SI • San Dwgo C» 92110 

|(71«>225 1040 • TWX 010 325 "M • Souic. TCB1M 

Full Ona Vaai Warianty • ViMl MaalafCnargc 






CIRCLE 236 ON READER SEHVICE CARD 



EDUCATIONAL 
PROGRAMS 

for Commodore's PET and VIC 






Software programs on cassette- 
elementary levels 32 programs— 4 
per month all PETS— $48.00 

Also a PET educational software 
catalog 300 programs $2.50 

COMM* DATA SYSTEMS 

-^ P.O. BOX 325 f^^ 

iRMILFORD, MI48042H W 
^^ (313)685-0113 ^^ 
Michigan residents add tax 



CIRCLE 126 ON READER SERVICE CARD 



AUGUST 1981 



151 



tIc U o9 AT,0NAL software 

TRS-80. COLOR COMPUTER PET 

& APPLE II 
ELEMENTARY MATH 
8CIENCE HI8TORY 

GEOGRAPHY ACCOUNTING 
ECONOMICS BUSINESSED 
FOREIGN LANG. COIN INVENTORY 
GRAMMAR FARM RECORDS 

Write for FREE Catalogue: 

MICRO LEARNINGWARE. Box 

2134, N Mankato. MN 56001 

(607) 625-2205 

VISA t MASTER CARD ACCEPTED 

We pay 15% royalty for Educational 
Programs listed with us. 

I?^5i s ^ a re 9istered trademark of 
TANDY CORP. 

^LJVJ rademark of COMMO- 
DORE BUS. MACHINES. 
APPLE is a trademark of APPLE 
COMPUTER CO 



CIRCLE 185 ON READER SERVICE CARD 




PROGRAMMES 
FOR THE 
SORCERER 



TAPE PROGRAMMES 

SUPERCALC Turn your Sorcerer mlo a desk-top calculator 26 
memories M transcendentels v tnJU 

«TOCK Complete Slock control Fully updatabie Mtmgs kept on 

^^S,"*!! ST"** 1 * 3?K 0, « ta T '«* •"" •«"«> etlecu 
Complete with Audio Unit *•■ ~ 

If 2£otlLr=o r " 5, °«'«™ «"" "vwage. and t rwWs » H so 
r«IH!? S *"* B ** c *" ln « *"*"• on tape Ea»y syntas 

CompWe programmer control E.cellenl ret.aoility bri 

URAF1X Define Graphics characters in macMne-latt time 
tun?" m * C '° •""■" Mock <«"«« E«My >"e bSt oTlTa 
UTaV 9 Make using your Development Pack a Breeze An 
functions automatic Many features „ 4 „ 

CP/M DISK PROGRAMMES 
Available on Micropenis Mod It 5V. 

S^'d^r' C ' "'— ««" C-ooum, sgem 

oSefSl^ leS?. " ""' "**" """ P "~°"' -""as 

SS!ri..'^" > "**" C, " e P">«'emme» by number horn a sorted 
"aenu hstmg ^ ^ 

nemt,'" " >8 ''*' "•••■"* E ""<>« LrfeBoal * Sorcerer are trade 



VtS'TofiZX"'*"""'- *—«-- CO«<*ETE c*.kou. 
ORDERS (m Australian Currency! to 



SOFTWARE SOURCE 

POBO' 3M. EdgechH 2027 Auetrelia 



CIRCLE 196 ON READER SERVICE CARD 



FREE 

business software 
directory 

• Radio Shack's Model I, II, HI. 

• Heath's MBASIC and HDOS. 
•CPM 

Data base manager, integrated 
accounting package, inventory, 
word processing, and advanced 
mailing list. 



^ 



Micro Architect Inc. 

96 Dothan St. 
Arlington, MA 02174 



CIRCLE 187 ON READER SERVICE CARD 



Power Plant, continued... 



2082 
2696 

2100 

2116 
2120 
2130 
2140 

2150 
2160 
2170 
2 1 86 
2190 
2195 
22&& 
5000 

3010 

3015 
3020 
3025 
3030 
3035 

3100 

3105 
3110 
3115 
3120 
3125 
3130 
3135 
3200 
3210 
3220 
3230 
3240 
3250 
3260 
3270 

4000 

4005 

4010 



4015 
4020 
4022 
4025 
4030 
4032 
4034 
4036 
4636 

404O 

4042 

4043 

4044 

4050 

4051 

4055 

4056 

4060 

4065 

4070 

4075 

4080 

4085 

4090 

4095 

5000 

5005 

5010 

5015 

5100 

5105 
5110 
5130 
5134 
5136 
5138 
5140 
5150 
5160 
5170 
5180 
5300 
5310 
5311 

6000 

6005 



DAY?i=DAV:.+MD?. : D4J.=DAYr. 

RDJi=0 

ED?i=0 

PD?i=0 

xnx-e 

SD?i=0 
GDX=0 
PB?i=0 
SB".'=0 
XB?.=0 
GBX=0 
EF:-.=0 PF?.=0 SFJ.=0 

ozx-e 

RETURN 

PR I NT " n*M«W" REM MELTDOWN END I NO 

IFRD?:>6GOTO3100 

PRINT"*! I HE REACTOR CORE HAS BEEN DESTROYED" 

PRINT-BY UNCONTROLLED THERMAL RUNAWAY "" 

PRINT" I0WEVER, THE CONTAINMENT BUILDING HAS" 

PRINT-NOT VET RUPTURED." ■«""•"« ■«» 

[£!!£!!! ?!^ TIflTE VClLlP EVACUATION PLAN." 00103208 
PRINT"* I HE REACTOR CORE HAS MELTED DOWN AND" 
PRINT-PRODUCED A STEAM EXPLOSION. I HE" 
PR I NT "CONTAINMENT BUILDING HAS RUPTURED " 

PRiNT T "^E Hfl ESCAPEI^ TIVE "«** ""» D ° R18 " 

ol?, 1 !^"*' • HITIflT E VOUR EVACUATION AND" 

PRiNT T "AsilsTAScE C " EftNUP *»« *'" ° ET MEDICftL " 

PRINT"HSW" 

FORZ5=1TO30 

PRINT'H VU-ntV JK-UTtv« \-1_|-To/» 

F0RZ6= 1 TO 1 00-3*25 : NEXT26 

PRINT'H SN-LI-TO/* \-LITo-' » -II -TV, a- 

FOR26=lTO100-3*25 NEXT26 ^°'~ 

NEXT25 

P0KE2 1 6 , 2 1 PR I NT GOTO5000 

REM EVALUATION OF GAME 

PRINT":! f-VER A PERIOD OF " DA:-; " DA VS . VOU HA"F" 

PRINT-PRODUCED AN AVERAGE POWER OUTPUT "OF" 



PRINT "l."KW>."K0. 

KiEKWH - IHD R LESS DEMANDING JOB?"' GCTO406T 

P JnT-^V^LoTvOU^R^ p H O fl W D R^E^S°^^T^60 BLftCKOUTS - 
PP mt-ISI ^? h - ° m RPEft HftD BROWNOUTS. " Gn?n4l60 
cc ftJI. "fi? T , BnD - OUR ftR EA'S POWER NEEDS" 
PRINT"WERE SUPPLIED - JU8T. - = OOT04660 

o* nT.'.'?5l QLIFlTE - DU C0ULI1 D0 BETTER." GOTO4060 

PRINT-EXELLENT! TOWER RATES IN VOUR AREA WILL" 

PRINT-NOT BE INCREASED. " GOTO4060 

PRINT"NEAR THE MAXIMUM! TOWER COSTS IN VOUR" 

PRINT"AREA WILL DROP SIGNIFICANTLY;- 

UOSUB2060 

IK= 1 - < DMX> 1 6 > - < DMJO20 ) - < DM?.>30 ) 

PRINT"* I HE EQUIPMENT DAMAGE SUSTAINED WAS" 

OHI«GOTO4080, 4085, 4090. 4095 ausmlNtu WM S 

PRINT"VERV LIGHT. " GOTO5000 

PRINT"MODERATE. " GOTO5000 

PRINT"SERIOUS. " 001*05608 

PRINT"SEVERE." 

REM END 

INPUT"W00ULD VOU LIKE TO TRV AGAIN" ;A* A*=LEFT*< A* n 

IFR*--V-THENB0SUB266e:00T039e LtFT*<A*,l. 

PR I NT "H" END 

B*="" 

F0RI=1T04 

GETA* 

I FASC < A* > 094THEN5 1 40 

IFB*=""THENRETURN 

0UT?i=VAL(B*> 

RETURN 

I F ASC < A* > = 1 3THENS VS50583 GOTO 1 1 70 

B*=B*+A* 

PR I NT A*: 

NEXT I 

RETURN 

FOR J6=1T063*24 NEXT J6 24=24+3 RETURN REM DELAV 

POKE216, 23= PRINT PRINT- TE3S •"■-- TO rntiTrNnP m. 

WAIT59410, 4, 4 P0KE216 , 23 PRINT PPINTBL* . GET-I RETMPN ' 

sn^"«aeea868aMe8a6aa*aMer lrlBL *' >*TiK» RETURN 

PRINT"3-:PRINTZH»-|HIS IS THE REACTOR VESSEL n- 



152 



CREATIVE COMPUTING 



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PRiwmmm a* a— sr &•• 

PRINT" Si i " 

F0RZZ=1T04 PRINT" JI a "NEXT 

PRINT" a "■ .S " 

PRINT" A tT" 

24=1 1 G0SUB5388 OO8UB5310 

PRINTZD*"IHIS IS THE CORE 

PR I NT " *WM«i«»H — " 

F0RZZ=1T03 FRINT"l»Hai "NEXT 

GOSUB5300 008UB53 1 8 

PRINT2B*"IHIS IS THE EMERGENCY COOLRNT 

PRINT"«S«W S^" 

PRINT" 3k »" 

PRINT", 91 " 

PRINT" Si" 

PRINT-"' •* ■" 

PRINT"* Sli ■" 

PRINT" 31" 

FORZZ= 1 T03 : PR I NT " '"NEXT 

GOSUB5300 G0SUB53 1 

PRINTZD*"IHESE ARE THE CONTROL RODS 

PRINT"«MM"TAB<5'"3ll" 

PRINTTRB<5>"3«I" 

PRINTTRBWir"" 

PRINTT8B(5>"an" 

PRINTTAB<5>"3f" 

24= 1 1 GOSUB53O0 GOSUB53 1 

PRINTZB*"IHIS IS THE PRIMAPV COOLflHT LOOP 

PR I NT" OMK" TAB' 12 »"■■" 

PR I NTT AB (12'" "a." 

PRINTTAB<13'"I" 

PRINTTAB<13>"I" 

PRINTTAB* 8 >" Shi 

PRINTTAB US)" I" 

PRINTTAB<8>"fc 

OOSUB5300 GOSUB33 1 

PRINTZD*"IHIS IS THE HEAT EXCHANGER 

PRINT"SM«««lW"TAB< 14) " a — ^ " 

PR I NT TAB- 14 I'fMI' 

PRINTTBB<14>"IHP" 

PRINTTAB' 14 ■ " a «M " 

PRINTTAB' 14 ■ " rl f* " 

24=11 OOSUBS380 0OSUB5310 

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PRINT TAB a* '"I 

PR I NT TAB U 8 VI 

PPIHTTAE< 16 >":•)■■ 



T' 



T 



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'TAB' 



I "TAB' 

I "TAB 
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31" 
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T 



PRINTTAB 

PRINTTAB(16V 
PRINTTAB<18>' 

PRINTTABC18)' 
PP1NTTAB<33>' 
PRINTTAB<33>' 

PRINTTAB 

PRINTTAB' 21 >' 

PRINTTAB' 21 >' 

OOS) IB5366 GOSUB5310 

PRINTZW'IHIS IS THE TURBINE 

PRINT'MMMmMMfTnB* 17 'Imh " 

PRINTTAB' 17 '"a-""" 

PPIHTTAB<17)"l""ai" 

PRINTTAB" 17 >"»■_■" 

GOSUB5300 GOSUB5310 

PRINTZD*"IHIS IS THE ELECTRIC GENERATOR 

PR I NT " eMWWHllrtiWlUBW" TAB < 1 > " 31 ■ ■ ■ ■■ " 

PRINTTAB' 10 '"31 ^" 

PRINTTAB' 10>" :■•■•■• " 

PR I NTT AB • 1 8 • " m *m—r 

Z4=ll GOSUB53O0 GOSUB3318 

PRINTZDf'lHIS 16 THE COOLING TOWER 

PRINT a MMNMMR' , TAB<24 '"si ""TABOO "I " 

PR I NTT ABC 24>" •a""TAB<30 •'" » " 

•A9m "TAB' 29'" *" 

I "TAB (29 -'"31 " 

I "TAB' 29 '"Si " 

|"TAB<29'"31" 
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GOSI IB53O0 QOSUB33 1 

PRINTZD*"IHIS IS THE COMPLETE DIAGRAM. 

GOSUB5310 PR I NT "3" ' P0KE59468, 14 RETURN 



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PRINTTABC 
PRINTTAB (26)' 
PRINTTAB' 
PRINTTAB' 26'' 
PRINTTAB' 25 ■■' 
PRINTTAB<25>" 



DON'T BE HELD UP! 



QUALITY 
SOFTWARE 

DISCOUNT 
PRICES 



Creative Discount Software 
256 S. Robertson, Ste. 2156 
Beverly Hills, CA. 90211 



CALL for our catalog 
TOLL FREE 

Operator 831 

800-824-7888 

Alaska/Hawaii 800-824-791 9 California 800-852-7777 

CIRCLE 139 ON READER SERVICE CARD 




World Class 



Your ATARI is a world class personal computer. But you 
need great software in order to exploit its capabilities. 
And you need information about how it all works. 

IRIDIS is a series of software packages that will help you 
enjoy and understand your ATARI more fully. The 
programs are outstanding, just as you would expect from 
the people who have published 23 issues of the widely 
acclaimed CURSOR Magazine for the Pet since 1978. But 
IRIDIS is more than just a collection of excellent 
programs. IRIDIS »2 comes with a 56-page manual that 
has clear, detailed explanations of how each program 
works. The explanations tell you line-by-line what each 
program does, and how it does it. 

IRIDIS and your ATARI: A winning team. World Class! 



IRIDIS #2 -Fondedit and Knotwork programs. 
Includes 56 page User Manual. 
$15.95 Cassette, $18.95 disk. 
Mastercharge and Visa welcome. 



Published By: 




Box 550 

Goleta, CA 93116 
805-683-1585 



CIRCLE 105 ON READER SERVICE CARD 



AUGUST 1981 



153 



% sensational 
>4pple II software 



creative 
computing 

software 



Air 



ic Controller 




Action Games 



Cassette CS-401 7 $11 95 



3 Games Requires 16K Apple II or Apple II Plus 




Cycle Jump Try to jump over rows of 
cars, buses and trucks 




Mine Rover Use your rover to cross t 
mine field with moving mines. 



Milestones 



Cassette CS-4015 $11 95 




Requires 48K Applesoft or Apple II Plus 



The object of Milestones is to complete a 
700 mile auto trip before your opponent. 
the computer You must deal with hazards 
of the roads slop lights flat tires, speed 
limits accidents and gas shortages Spec- 
tacular high-resolution color graphics 




Road Machine Drive over a curving, 
mountain road as fast as possible Eight 
skill levels 



Bumping Games 

Cassette CS-4020 J 1 1 95 3 Programs Requires 16K Apple II or Apple II Plus 



' - - . 

^ " " ' 




Obstacle Course This multilevel course Hustle. The score keeps building but the 
includes hurdles ladders tires and escape routes dwindle Can you reach the 
penally areas Different every lime blocks before they disappear'' 



Action & Bumping Games 

Disk CS-4516. $24 95 

Requires 32K Applesoft or Apple II Plus 

This disk contains all six games from cassettes 
CS-401 7 and CS-4020 

Milestones 

DiskCS-4515 $19 95 

Requires 48K Apple II or Apple II Plus 

In addition to the game itself this disk contains 
the complete playing instructions 



Advanced 
Air Traffic Controller 

DiSkCS-4517. S19 95 

Requires 16K Apple or Apple II Plus 

This price is an advanced version of Air 
Traffic Controller I Cassette CS-40081 offering 
additional features and challenge 




Bumper Blocks. An absorbing game of 
evasion and collision Five skill levels 



Order Today 



To order any of these software packages 
send payment plus $2 00 postage and 
handling per order to Creative Computing 
Morris Plains NJ 07950 Visa MasterCard 
and American E x press orders may be called 
in toll-tree 



Order today at no risk If you are not 
completely satisfied your money will be 
promptly and courteously refunded 

Creative Computing Software 

Morris Plains NJ 07950 

Toll-free 800-631-8112 

In NJ 201-540-0445 



creative coneputtRg software. 



Ace* « m« r»giat»rM trKtomark of Appkt Compute*, inc 



CIRCLE 300 ON READER SERVICE CARD 



« 

>4ppfe II 



sensational 

software 



creative 

compatfRg 

software 



CAI Programs Vol I 



Cassette CS-4201 $11 95 



Requires 16K Apple II or Apple II Plus 




r RIGHT wrong WROei 
5i 9 e» \ 



MINT 
CARBURETOR 

• CPRBURETOr'' 

SUPER 

»RESS ONV kEV FOR NEXT MORO 
PRESS •%• TO STOP 



Ecology Simulations - / 



US Map Identify statesandtheircapitals Spelling Studyaid with your list of trouble- 
some words 



8*1=9 
UOU ■ ! i 



• *» HITH CflfiftV • • 

•n 

is? 

♦594 
'OU SET a GRBOE OF 0' 



Math Drill Arithmetic drill and practice with Add With Carry Drill and practice on sums 
large or small display requiring numbers to be carried 



Disk CS-4706 $24 95 

MhI 

STERL allows you to investigate the 
effectiveness of two different methods ol 
pest control — the use of pesticides and the 
release of sterile males into a screw-worm 
fly population The concept of a more 
environmentally sound approach versus 
traditional chemical methods is introduced 
In addition. STERL demonstrates the effec- 
tiveness of an integrated approach over 
either alternative by itself 



Requires 48K Applesoft in ROM or Apple II Plus 




The POP series of models examines three 
different methods ol population projection, 
including exponential. S-shaped or logistical 
and logistical with low density effects At 
the same time the programs introduce the 
concept of successive refinement of a model. 
since each POP model adds more details 
than the previous one. 

Tag 

TAG simulates the tagging and recovery 
method that is used by scientists to estimate 
animal populations You attempt to estimate 
the bass population in a warm-water, bass- 
bluegill farm pond Tagged fish are released 
in the pond and samples are recovered at 
timed intervals By presenting a detailed 
simulation of real sampling by tagging and 
recovery. TAG helps you to understand 
this process 

Buffalo 

BUFFALO simulates the yearly cycle of 
buffalo population growth and decline, and 
allows you to investigate the effects of 
different heard management policies Simu- 
lations such as BUFFALO allow you to 
explore what if questions and experiment 
with approaches that might be disatrous in 
real life 



CAI Programs Vol II 



Cassette CS-4202 $1195 



Requires 16K Apple II or Apple II Plus 




European Map Identity countries and 
their capitals 



Music Composing Aid Make and play 
your own music on the Apple No addi- 
tional hardware required Includes a 
sample from Bach s Tocatta A Fugue in 
minor 




i Learn math skills by destroy- 
ing menacing meteors 




CAI Programs I and II Stock & Options Analysis 



Disk CS-4 701 $24 95 
Requires 32K Integer Basic 



DiskCS-4801 $99 95 

Requires 32K Applesoft or Apple II Plus 



This disk contains all 7 programs from cas- This ,» a comprehensive set ol lour programs 

settes CS-4201 and CS-4202 iq, me investment strategy ol hedging listed 

options against common stocks A complete 
description is in the TRS-80 section Available 

Note The ecology simulations programs August 1981 

are not available on cassette 



Ecology Simulations - // 



DiskCS-4707$24 95 



Requires 48K Applesoft in ROM or Apple II Plus 



Pollute 

POLLUTE focuses on one part of the water 
pollution problem, the accumulation of certain 
waste materials in waterways and their effect 
on dissolved oxygen levels in the water 
You can use the computer to investigate 
the effects of different variables such as 
the body of water, temperature, and the 
rate of dumping waste material Various types 
ol primary and secondary waste treatment 
as well as the impact of scientific and 
economic decisions can be examined 




Rats 

In RATS, you play the role of a Health 
Department official devising an effective, 
pratical plan to control rats. The plan may 
combine the use of sanitation and slow kill 
and quick kill poisons to eliminate a rat 
population It is also possible to change the 
initial population size, growth rate, and 
whether the simulation will take place in an 
apartment building or an eintire city 

Malaria 

With MALARIA, you are a Health Official 
trying to control a malaria epidemic while 
taking into account financial considerations 
in setting up a program The budgeted use 
of field hospitals, drugs lor the ill. three 
types of pesticides, and preventative medica- 
tion, must be properly combined for an 
effective control program 

DM 

DIET is designed to explore the effect ol 
four basic substances, protein lipids, calories 
and carbohydrates, on your diet You enter 
a list of the types and amounts of food eaten 
in a typical day. as well as your age. weight, 
sex. health and a physical activity factor 
DIET is particularly valuable in indicating 
how a diet can be changed to raise or lower 
body weights and provide proper nutrition 



Order Today 



To order any of these software packages 
send payment plus $2 00 postage and 
handling per order to Creative Computing 
Morris Plains NJ 07950 Visa MasterCard 
and American E x press orders may be called 
in toll-free 



Order today at no risk It you are not 
completely satisfied your money will be 
promptly and courteously refunded 

Creative Computing Software 

Morris Plains NJ 07950 

Toll-free 800-631-8112 

InNJ 201-540-0445 



creative coraputiRg sort, whit, 



AMtt * in* r*ga»k>**a •raawntrli or Appt* Computer mc 



CIRCLE 300 ON READER SERVICE CARD 



Stoo 



«BfcW«*«* 



f&m 



Welcome to Stoneville Manor. This 
dream mansion can be yours, all yours, 
once you have obtained the deed. To get 
the deed, you need only open the safe. 
To open the safe you need only .... 
Well, we'll let you And that out for yourself. 
It will suffice to say that there are many 
surprises along the way. 

Stoneville Manor is written in Applesoft, 
and requires 16K of free memory. Since 
this adventure might take some time to 
complete, a save-game feature is included 
which allows you to store the present 
status of the game on disk. To do this, 
give the command SAVE GAME. When- 
ever a new game is started, the combination 
of the safe changes. Good luck, and may 
all your deeds be legal. 



Rundv Jensen. 12501 Doons Dr.. Oklahoma City. 
OK 731.12. 



Randy Jensen 



Id HOME :L - 9 

56 DIM I*<33).0*<33),0C33>,L#<:37 

..,D*<3.37',D<3,37> 
100 VTAB <11>: HTAB <12> 
110 PRINT "STONEVILLE MANOR" 
400 FOR X = 1 TO 33 
410 READ I*<X>.0#<X>.0<X> 
420 NEXT X 
430 FOR X « 1 TO 37 
440 READ Lf<X> 
450 NEXT X 
460 FOR Y = 1 TO 37: FOF X 

T 

470 READ D*<X,Y.>.D<X,Y> 

480 NEXT XI NEXT Y 

49G FOR X = 1 TO 3 

590 READ P»CX) 

510 NEXT X 

156 



1 TO 



520 


FOR X = 1 TO 8 


536 


READ VE 


540 


me: 1 


550 


FOR X = 1 TO 3 


sue 


Z = INT <89 * RNI ■ 1 • + 11 


570 


N*<X> « STR* <Z> 


58© 


NEXT X 


590 


FOR X = 1 TO 3 


600 


Z = INT (3 t PNC ( 1 ■ ■■ ♦ 1 


610 


IF S<2) ■ Z THEM 600 


620 


:*■•;•= tit : " • = Z 


625 


he: :: 


630 


HOME : ','ThB (10) 


640 


PRINT SPC< IE •"CREATED BY" 


650 


PRINT 3PC< 14P "RANDY JENSEN 


660 


VTAB ;;■: HTAB <8> 


670 


INPUT "DO YOU WANT INSTRUCT! 



0NS?"JC* 



CREATIVE COMPUTING 




r Maker D: 

it not only does more titan VisiCalc, 

it does it on your computer. 



VisiCalc is a fine aid for the computation of numerical 
problems. But it does have two major limitations: it is 
available only for a small number of systems, and its use 
is limited strictly to numbers, not words. To overcome 
these substantial limitations, Lifeboat Associates intro- 
duces T/Maker II. 

Unlike VisiCalc, T/Maker II is designed to run on most 
small business computers with CP/M* or similar operat- 
ing systems and a video terminal with cursor addressing 
capabilities. And soon there will be T/Maker II versions 
available for UNIX,'" RT-11'" and other systems. 
Works with word* as well as numbers. Like VisiCalc, 
T/Maker II reduces the manual tasks involved in comput- 
ing and calculating financial documents. But since most 
business problems and reports involve words as well as 
numbers, T/Maker II also functions as a full-screen text 
editor for word processing. 

T/Maker II is the most advanced aid for the analysis and 
presentation of numerical data and text material. In a 
matter of minutes, an entire document— including all 
edited text, all figures and all calculations— can be created, 
reviewed on your screen and reported in printed form. 

T/Maker II turns your small business computer into a 
powerful, sophisticated and convenient tool. A tool that 
will save you money, time and energy, and eliminate the 
need for costly time-sharing. 

With T/Maker II you can easily perform an unlimited 
number of analytical and reporting tasks which integrate 
numerical and text processing. You'll find T/Maker II per- 
fect for such things as: 



• Financial Statements 

• Statistics 

• Profitability Reports 

• Revenue and Expense 
Analyses 

• Portfolio Evaluations 



• Price Lists 

• Rate Structures 

• Expense Accounts 

• Cash Flow 
Projections 

• Checking Account 
Reconciliations 



rows and columns, define the relationships and T/Maker II 
will do the rest: it will perform the computations and for- 
matting necessary to prepare your document. When 
you're finished you can analyze your report on your 
screen or store it on a diskette. Or, you can have the report 
printed with presentation quality. 

And when any changes have to be made, simply enter 
the new figure or relationship and tell T/Maker II to adjust 
and recalculate all the new results. 
Editing capabilities. As a full-screen editor for word 
processing, T/Maker II handles text up to 255 characters 
wide. It includes features like text formatting and justifica- 
tion, centered titles, a text buffer for block moves and 
repeated inserts, global search and replace commands 
for printing your letters, reports and documents. Wide 
documents are supported by horizontal scrolling. 
Low cost. The cost of T/Maker II is only $275 plus shipping 
and handling. Dollars well spent once you consider all the 
time, energy and money it can save. T/Maker II is brought 
to you exclusively and supported completely by Lifeboat 
Associates, world's largest computer software publisher. 
For more information send us the coupon below. 

' Mail coupon to: Lifeboat Associates, 2601 

I 

I 
I 
I 
I 
I 
I 
I 
I 
I 
I 



Mail coupon to: Lifeboat Associates, 

1651 Third Ave. . NY, NY 10028. Or call (212) 860-0300. 

□ Please send me more information on 
T/Maker II. 

n Please send me a free Lifeboat 
Catalog featuring over 200 programs, 
including integrated accounting 
and professional practice systems, 
office tools for bookkeepers and secre- 
taries and sophisticated tools for pro- 
grammers. 



Name- 

tm« 



Company- 
Street 

City 




-Zip— 



T/Maker II is a trademark ot P. Roizen. 
CP/M is a trademark ot Digital Re- 
search. Inc. VisiCalc is a trademark of 



PersonalSoll ware. Inc. UNIX isatrade- 
mark ot Bell Laboratories. RT 11 is a 
trademark of Digital Equipment Corp. 



. . .and much, much more. 

Easy to learn and use. You don't have to be a program- 
mer to operate T/Maker II. lust follow T/Maker lis easily 
understood and ordered instructions, set up your data in 
As an example oi what T/Maker II can do. see the chart below. The operator entered only the data shown in boldface. 

T/Maker II calculated and reported all the other values. 



Item A 
ItemB 
Total 

% Item 
% hem 
Total 



1978 

42.323 
45.671 
87,994 

48.10 

51.90 

100.00 



— Actual — 
1979 


1980 


Growth 
Rate 


Average 


Total 
(OOO's) 


1981 


—Projected— 
1982 


1985 


51.891 
46.128 

98.019 


65.123 

49.088 

114,211 


24.04 

3.67 

13.93 


53,112 
46,962 

100,075 


159.34 
140.89 
300.22 


80.782 

50,891 

131,673 


100,206 

52,761 

152,966 


191,262 

58,791 

250,053 


I 52.94 
) 47.06 
) 100.00 


57.02 

42.98 

100.00 


8.88 
-9.00 


52.69 

47.31 

100.00 


158.1 
141.9 

300.0 


61.35 

38.65 

100.00 


65.51 

34.49 

100.00 


76.49 

23.51 

100.00 



Liteboat Associates 

1651 Third Ave 

New York N Y 10028 

Id (2121 860 0300 

We. 640893 (IBSOfl NrK) 

TWX 710 581-2524 



ht.boat Inf. 

OKBtdt 5f 

I 2 8 Shiba Daimon 

MMM lb Wm 105 Japan 

lei 03437 3901 

We. 2422723 IASRTV01I 



LIFEB01T WOdlDWIOE otters rou the worlds largest library ot software Contact your nearest dealer or LiteDoat 

Litetnal Associates GmbH Intersott GmbH 

P0 Bon 168 Aeienstrasse 35 Scfilossiaitenwej 5 

CH 6340 Baat Switzerland D-«045lsmamn| * German, 

let 042 31 2931 Tel 089-966-444 



lifeboat Associates ltd 

TO Bo. 125 

London >VC2H 9LU England 

Tel 01 836-9028 



Tela 893709 HBSOfTGl 



Tele. 865265 (MIC0 CHI 



Tele. 5213643 IISOF0I 



lifeboat Associates. SARI 

10 Grande Rue Charles de Gaulle 

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Tel 1-733 08-04 

Tela 250303 IPUBUC X RARISI 



lifeboat Associates 

Software with full support 
CIRCLE 216 ON READER SERVICE CARD 



Stoneville Manor, continued. 

680 IF LEFT* CCt.lJ * "V" THEN 

GOSUB 7S00 
786 HOME I VTAE <12» HTaB (2> 
710 INPUT "DO YOU WANT TO CONTIN 

UE AN OLD GAME : '":C* 
720 IF LEFT* CC».l) = "V" THEN 

QOSUE 8300 
100O HOME 
1010 PRINT : INVERSE : PRINT "LO 

CATION:": NORMAL : PRINT L*< 

L) 
1020 PRINT : INVERSE : PRINT "DI 

RECTI ON:": NORMAL 
1036 FOR X = 1 TO 3 
1040 GOSUB 5080 
1050 NEXT :: 
1060 PRINT : INVERSE : PRINT "VI 

SABLE OBJECTS:": NORMAL 
1070 IF L = 30 AND 0(13) < > THEN 

1190 
1075 IF L = 31 AND 0<13> < > 8 THEN 

1190 
1035 FOR X = 1 TO 33 
1090 IF •'.■: = L 'HEN FRINT I ' 

1180 NEXT X 

1110 GOSUB 5280 

1190 PRINT : INPUT "NOW UHAT'":C 

* 
1228 IF LEFT* <C*.3> = "GET" THEN 

203O 
1225 IF C* = "DROP SNORKEL" THEN 

3648 
1238 IF LEFT* <C*.4> = "DROP" THEN 

2198 
1240 IF LEFT* CC*,3> = "TAKE IN 

V" THEN 2350 
1268 IF Ct = "ENTER VENT" THEN 2 395 

1270 IF C* = "ENTER BALLOON" THEN 

2540 
1288 IF Ct = "ENTER LAKE" THEN 2 

688 
1298 IF C* = "ENTER DOOR" THEM 2 

658 
1308 IF C* = "ENTER STORE" THEN 

2688 
1320 IF LEFT* (C»,5) = "ENTER" THEN 

2750 
1348 IF LEFT* CC*,8) = "EXAMINE 

" THEN 2846 
1358 IF LEFT* <Ct,S> = "LOO) " THEN 

2SS0 
1368 IF LEFT* CC*,6) = "GO JOG" 

THEM 3000 
1370 IF LEFT* CC#,4> = "GO E" AM 

L = Z2 THEN 3950 
1388 IF LEFT* X»>4) = "8C 0" THEN 

3035 
1398 IF LEFT* CC*.2) = "GO" THEN 

30S8 
14O0 IF C* = "FET SERUM." THEN 3 

130 
1418 IF C* ■ "FEED 3ERVAL" THEN 

3150 
1420 IF C* = "GIVE TROUT" THEN 3 

150 
1430 IF LEFT* X*.8> = "CUT TRE 

E" THEN 3190 
1435 IF LEFT* CLIO' = "CLIMB 

TREE" THEN 3808 
1440 IF LEF~* CC*,9) ■ "CHOP TP 

EE" THEN 3190 
1450 IF LEFT* :c*.4:i = "DIVE" THEN 

32 1 
1460 IF C* = "END SAME" THEN HOME 

: END 
1478 IF LEFT* :*.T- = "BUY" H NI 

L « 10 THEN 2868 
1475 IF C* = "REMOVE COVER" THEN 

3250 
1480 IF LEFT* C*. ? • = "OPEN VE 

NT" THEN 3250 
1485 IF C* = "OPEN BOOK" THEN 28 

50 
1498 IF C* = "OPEN DOOR" THEN 32 

95 
1495 IF C* = "OPEN CREDENZh" THEN 

2850 
1500 IF C* = "OPEN FSAlV' THFN ?RF 



1510 
1520 
1540 
1550 
1560 
1570 
1530 
1598 
1680 
1605 
1610 
1620 
1990 
2030 



IF C* = "OPEN SAFE" THEN 70 
80 

IF C* = "UNLOCK DOOR" THEN 
3295 

IF C* = "INFLATE FAFT" THEN 
""SO 

INFLATE BALLOON" THEN 



IF C* = 
33S0 

IF C* = 
3330 

IF Ct = 
3460 

IF Ct = 
3460 

IF C* = 



"BUILD BALLOON" THEN 
"FLY BALLOON" THEN 
"SAIL BALLOON" THEN 



READ WILL" AND F = 
1 THEN 720O 

IF Ct = "READ BOOK" THEN 28 
50 

IF C* = "REhC SI6N" THEN 39 
00 

IF C* = "SAVE GAME" THEM 34 
00 

IF Ct = "CLEAF SCREEN" THEN 
1000 

PRINT "DON'T UNDERSTANDS GOTO 
1190 

IF C* = "GET TROUT" AND L = 
29 AND 0< 18 8 'HEN PI 
"IT 3LIPPED OUT Or YOUR HhNC 
S"l GOTj 1190 
2035 IF Ct = "GET PICTURE" AND L 
= 16 THEM FRINT "TO VALUA8 
LE": GOTO I I 
2040 IF L = 10 THEM FRINT " 
ONLY BUY FROM STORE": 601 
198 
2045 IF Ct = "GET ThBLE" AMI 

37 THEN print "IT'S NAILED 
DOUN"l QOTO 1198 
2050 IF S = 1 THEM' 6808 
2055 IF I ■ 4 THEN PRINT "IHVEN 

TORY TC HEAVY"l 80T0 
2060 IF Ct = "GET MASK" THEN 

8 
206S IF C* = "GET SNORKEL" THEM 

6100 
2070 for :■: = i TO 19 
208O G = LEM • I r 
2090 IF MID* :C*,S „h[ 

■ 8 THEN PRINT "ALREAD 
Y HA"E OBJECT"! SOTO 1138 

2100 IF MIC* Xt.S.S) = I* 

■ L them .; :: , = 0:1 = I 
♦ 1 : 80TO : • 

2110 NE 

2120 IF Ct = "SET 3ERVAL" AM 

30> ■ L T HEM 621 
-130 IF Ct = "GET CREDENTA" hND 
L « 14 THEN FFIN LI 
FT IT": GOTO 1198 
2140 IF C* = "SET ■:<*-!.£■■ SNI 

' ■ L THEN PF ;: = 

TY": GOTO 1198 
2150 IF C* = "QET SAFE" AMD t 

> = I 'HEM PRINT "SAFE 13 : 
ECUPED TO WALL": GOTO 1190 
2170 GOTO 1990 
2190 FOR X = 1 TO 19 
2200 G = LEN a*<X>> 
2210 IF MID* <C*,6,G> = I*(X> AND 

: =0 THEN 2240 
2220 NEXT X 
2230 GOTO 1990 
2240 IF X ■ 8 AND L = 28 THEN 0( 

8> - 61 1 ■ I - l: FLASH : PRINT 

"RrtFT DRIFTS AWAY": FOR X = 

1 TO 3080: NEXT XI NORMAL : GOTO 

1000 

2245 IF X = 8 AND L = 29 THEN 0< 

- El I - I - II FLASH : PRINT 

"RAFT DRIFTS AWAY": FOR X » 

1 TO 3000: NEXT X: NORMAL : GOTO 

1000 

2270 1*1-1 

2280 IF L = 28 THEN 0<X> = 30: GOTO 

1000 

2290 IF L = 29 THEN 0<X> = 31: GOTO 

1800 
2300 0<X> = L: GOTO 1000 



2350 

2360 

2370 
2388 
2395 
2408 
2405 
2410 
2415 

2420 

2425 

2430 

2450 

2460 

2470 

2430 

2435 

2490 

2580 

2510 

2520 

2530 
2540 

2558 

2560 

2570 

2688 
2610 

2638 

2648 
2658 

2655 

2660 

2678 

2680 



FOR X ■ 1 TO 19 

IF 0<X> = 8 THEN PRINT 0*<; 

next :: 

GOTO 1198 

FOR X = 1 TO 8 

IF VE(X> = L THEN 2415 

NEXT :: 

GOTO 1990 

IF 0<3> = 6 AND P = 1 THEN 

PRINT P*<2>: GOTO 1190 

FOP X » 1 TO 4 

IF 0<X> = O THEN PRINT P*C 
OTO 1190 

NEXT X 

IF L = 13 AND CI = THEN PRINT 
P#a.>: GOTO 1198 

IF L = 14 AND C2 = THEN PRINT 
Pt(l>: GOTO 1198 

IF L = 17 AND C3 = THEN PRINT 
P$( 1 •: GOTO 1190 

IF L = 18 AND C4 = THEN FRINT 
P*< 1 )l GOTO 1190 

IF U = THEN PRINT "YOU W 
EIGH TO MUCH": GOTO 1190 



IF L 
= 21: 
IF L 
= 24: 
IF L 
= 2*: 
IF L 



= 1 THEN L 



"NOT P 



= 13 AND CI = 1 THEN L 

GOTO 10OO 
= 14 AND C2 

GOTO 1000 
■ 17 AND C3 = 1 THEN L 

GOTO 1008 
= 18 AND C4 = 1 THEN L 
= 27: GOTO 1000 
GOTO 1990 

IF H = THEN PRINT 
EADY YET": GOTO 1190 

IF L = 3 THEN L = 34: GOTO 
1080 
IF L = 

1800 

PRINT 
90 

IF L < > 5 THEN 1998 

IF 0<8> < > THEN PRINT 
"NEED SOMETHING TO FLOAT ON" 
: GOTO 1190 

IF R = THEN PRINT "RAFT 
IS TO FLAT": GOTO 1190 
L = 28: GOTO 1868 

IF L = 16 AND K = THEN PRINT 
"DOOR IS LOCKED" 

IF L = 28 THEN L 
: GOTO 1000 

IF L = 16 THEN L 

1000 

GOTO 1990 

IF L < > 9 THEN 



36 THEN L = 35: GOTO 
"CAN'T FIND": GOTO 11 



GOTO 1190 
16:K = 1 

28: GOTO 



GOTO 1998 



2690 FOR X » 1 TO 19 

2708 IF OCX) = 8 THEN PRINT "CA 

N'T ENTER STORE (JITH INVENTO 

RY": GOTO 1198 
2718 NEXT X 
2728 L = 18: GOTO 1OO0 
2758 IF C* = "ENTER MANOR" AND L 

= 9 THEN L = 12: GOTO 1000 
2768 IF C* = "ENTER MANOR" AND L 

■ 1 THEN L = 17: GOTO 1000 
2778 IF Ct = "ENTER HOSPITAL" AND 

L = 9 THEN L - 111 GOTO 1000 

2780 IF Ct = "ENTER TUNNEL" AND 

L = 31 AND 0(13' = O THEN L = 
32: GOTO 1080 
2790 IF Ct = "ENTER CREEK" AM) L 
= 4 THEN FLASH : FRINT "YO 
U SLIPPED AND FELL": FOP X = 
1 TO 3800: NEXT XI NORMAL IS 
= UL = 11: GOTO 1000 
2800 IF Ct = "ENTER GORGE" AND L 
= 3 THEN PRINT "TO STEEP" I 
GOTO 1198 
2818 IF C* = "ENTER SHACK" HUD L 

■ 36 THEN L = 37: GOTO 1008 

2820 GOTO 1990 

2840 G = LEM | j:r>* = mid* 

<C*,9,G>: GOTO 2360 
2850 G = LEN •■:*> - 5:0* = mid* 

-CI. 



158 



CREATIVE COMPUTING 




Lynn Busby, president of the Computer Station, as seen by the Dithertizer II. 



Dithering Developed at Bell Labs and 
MIT. dithering was originally an approach 
to picture transmission. Compared to other 
methods, dithering is fast and accurate. 

The Dithertizer II was designed for the 
Apple computer by David K Hudson, a 
researcher at MIT Design goals were high 
accuracy, fast scanning, maximum reliability 
and an economical price 

High Quality Images 

The resolution is of the Dithertizer is the 
maximum the Apple can handle in the high- 
resolution mode, i.e . 280 x 192 (53.760) 
pixels 

To produce an image, a video camera is 
focused on the subject Peripherals Plus 
furnishes a Sanyo VC1610X camera, a 
laboratory/industrial unit with an f 1 .6 lens. 
This camera has a focus range of 18 (for 
extreme close ups) to infinity (for distant 
subjects) 

The camera scans an entire frame in 1 /60th 
of a second Two frames are scanned, of 
course, in 1 /30th of a second By adjusting 
the blackness control (with Paddle 1 to any 
one of 255 levels you can determine the 
threshold of gray between the two frames 

A 1 /30th second, two-frame scan has two 
levels of gray and produces a high-contrast 
but quite recognizable image 

Pictures or Contours 

Using the Contour software routines and 
contrast control (Paddle 1 ). it is possible to 
subtract one image from another If the 
blackness thresholds of the two images are 
close, say 125 and 127. the resulting image 
will show just the outlines or highlights of 
an object 

Another possibility is to reduce the contrast 
to zero which results in a nearly blank screen 
except for movement in the area scanned 



This type of movement detector is much 
faster (l/30th second) and more precise 
than other much more expensve systems 
It is currently being used to detect and record 
movement of laboratory animals. It is also 
used in security installations 

The "Dithering' software routines use the 
contrast control to divide an image into gray 
tones. As mentioned above, two levels 
(usually white and black) result in a high 
contrast image. Four gray levels provide 
additional definition while sixteen levels 
produce a highly detailed image in just over 
1 /4th of a second Extremely high detail is 
possible using the highest 64-gray level 
setting. At this level, an image is produced 
in 64/60ths of a second or just over one 
second. The quality of this image is close to 
that of a halftone photograph found in a 
newspaper or magazine. 

Using Dithered Images 

What can one do with a dithered image? 
Upon completion it can be stored automatic- 
ally in either page 1 or 2 of the high-resolution 
graphics area of the Apple Hence, itcanbe 
printed out on practically any printer To 
print it on an Apple Silentype printer or 
equivalent requires no additional software. 

To take advantage of the automatic print 
routines in the Dithertizer itself does require 
additional software tailored to a specific 
printer Software packages are available at 
$44 95 each for the following printers: IDS 
440. 445. 460. and 560; IP225; Anadex 
DP9500and DP9501; Spinwriter 5510 and 
5520 

Individual images or series of images may 
also be incorporated in other programs in 
the same way that other hi-res graphics are 
used Using VersaWriter software, for exam- 
ple, text may be added to images. An image 
may be shown on the screen while a disk is 



You and your Apple can have 
a new view of the world. 



Dithertizer! 



loading or while the computer is completing 
a time-consuming calculation in another 
program 

With the proper software, the Dithertizer 
can be used to perform image enhancement, 
to identify features, detect motion, track a 
moving target or create a detailed picture 
for display The possibilities are limited only 
by your imagination 

Quality Construction 

The dithertizer is manufactured to exacting 
specifications by Computer Station It consists 
of the Dithertizer II board which plugs into 
Slot 7 in the Apple 1 1 . a cable which connects 
between the Dithertizer and motherboard 
and a 10 foot cable to the camera The 
system requires a 48K Apple disk system. 

The software package consists of three 
routines on disk: Dither to build a gray 
scale picture. Contour to produce an edge 
scan using image subtraction, and Dscan 
to store a binary image in either page 1 or 2 
of the high-resolution graphics area 

Peripherals Plus also includes a Sanyo 
VC 1 6 1 0X video camera with external hori- 
zontal and vertical sync input. 

The components of the packge — hardware, 
software and camera -are warranteed by 
the manufacturers against defects in material 
and workmanship for 90 days In addition. 
Peripherals Plus guarantees that if you are 
not completely satisfied you may return the 
system for a prompt and courteous refund 



Order Today 

The entire Dithertizer system consisting 
of the Dithertizer board. Sanyo camera, 
cables and software costs only $650 plus 
$6 shipping and handling in the continental 
United States. Customers in other loctions 
should write for shipping rates. Price for 
the board and software alone is $300 while 
the camera alone is $410 To order your 
system, send payment or Visa. MasterCard 
or American Express card number and 
expiration date to the adress below Credit 
card customers may also call orders to our 
toll-free number. 

Don t put it off Remember, your system 
is backed by both manufacturer warranties 
and a complete moneyback guarantee of 
satisfaction from Peripherals Plus 

Give your Apple a new view of the world 
with a Dithertizer Order today 

39 East Hanover Avenue 

Morris Plains, NJ 07950 

Toll-free 800-631-8112 

(In NJ 201-540-0445) 



CIRCLE 239 ON READER SERVICE CARD 



Stoneville Manor, continued. 



2369 

2S70 

2875 

2830 
2890 
2900 

2910 

2920 

2938 



2940 
2968 



2960 
2970 
2980 

3000 
3010 

3015 

3020 

3025 
3030 

3040 

3050 

3860 

3070 

3080 

3090 
3100 

3110 
3120 

3130 

3140 
3150 

3160 
3170 

3180 

3185 

3190 



3208 

3210 



3215 

3220 
3225 



I TO 33 

I*(X> AND 0(X) 



L THEN 
THEM 



THEM PRINT 



PRINT 



FOR X 

IF Q* 
2900 

IF Q* = I$(X) AND OOO 
2900 

NEXT X 

GOTO 1990 

IF Q* = "BOTTLE 
P*(3)lN*(l)l GOTO 1190 

IF 0* = "GOBLET" THEN 
P*(3);N*(2>: GOTO 1190 

IF Q* = "TABLE" THEN PRINT 
"OH TOP IS A NOTE WITH THE N 
UMBER "!N*(3>: GOTO 1190 

IF Q* « "CASE" THEN PRINT 
"ONE BOTTLE IS MISSING": GOTO 
1190 

IF Q* « "BOOK" THEN 6S50 

IF Q* = "CPEDENZA" AND 003 
) * 40 THEM PRINT "INSIDE I 
S A SWIM MASK": GOTO 1190 

IF 0* = "BAG" AND 0(19) = 4 

THEN PRINT "INSIDE 13 A S 
NOPKEL": GOTO 1190 

IF G* = "PICTURE" THEN FRIMT 
"BEHIND PICTURE IS A SAFE":E 

= II GOTO 1190 

PRINT "NOTHING UNUSUAL": GOTO 
1190 

IF 0(11) < > THEN PRINT 
"NEED SHOES": GOTO 1190 

IF L > 9 THEM PRINT "CAN'T 

JOG HERE": GOTO 1190 
U ■ l: PRINT "WHEW '...DONE": 

GOTO 1190 

IF L = 28 THEN L = 5: GOTO 

1000 

GOTO 1990 

IF S = 1 THEM PRINT "NOT W 
ELL": GOTO 1190 

IF L = 21 AND CI 
P*(l>: GOTO 1190 

IF L = 24 HMD C2 
P*< 1 :■: GOTO 1196 

IF L = 26 AND C3 
P*(l)l GOTO 1190 

IF L ■ 27 HMD C4 = THEN PRINT 
P*(l)i GOTO 1196 

IF LEFT* rj.4. 
L - 18 THEN 6300 

FOR X = 1 TO 3 

IF MID* • CI, 4.1 

THEN L = D(X,L)I 

NEXT X 

PRINT "DIRECTION NOT CLEAR" 
: GOTO 1198 

IF V = B AND L = 18 THEN 62 

00 

GOTO 1990 

IF V = 1 THEN 1990 

IF L ! 18 THEN 1990 

IF 0(14) JR L : 1 
3 THEN PRINT "MEED FOOD": GOTO 
1190 

FLASH : PRINT "SERVAL TOOK 
TROUT AND ESCAPED"! IF 0< '14 > 

■ 8 THEN 1 = 1-1 
V ■ 110(14) = 4010(30) ■ 40: 
■ 1 TO 3000: HE: 

NORMAL : GOTO 1888 

IF L = 2 ANC 0(12) = OF 
= L THEN 0(4) = 2: GOTO 

looe 

GOTO 1990 

IF L = 28 AND 0(8) = AND 

0(19> " THEN 0(8) = 5:1 = 

1 - IIL ■ 30: FLASH I FRIMT 
"RAFT DRIFTS AWAY": FOP X = 

t TO 30OO: NEXT XI NORMAL I GOT 3 

1000 

IF L = 29 hMD 0(8) = AND 
0(19) = O THEN 0(8) = 5: I = 
I - HL ■ 311 FLASH : FRIMT 
"RAFT DRIFTS AWAY "I FOP :: ■ 
l Ti" 7WW: mf::t ::: NflRMAI : fi 

IF L = 28 AND 0(19) * THEN 
L = 30: GOTO 1080 

IF L » 29 AND 0(19) = THEN 
L * 31: GOTO 100O 



THEM PRINT 



THEN PRINT 
O THEN PRINT 



"GO E" AND 



D*(X.L) 

GOTO 1600 



3230 IF L = 28 OR L = 29 THEN PRINT 5010 

"NEED SNORKEL": GOTO 1190 
3240 GOTO 1998 

3250 IF L = 13 THEN CI = If GOTO 

1000 

3255 IF L ■ 21 THEN CI - H GOTO 

1000 
3260 IF L = 14 THEM C2 « U GOTO 

1 000 
3265 IF L = 24 THEN C2 = li GOTO 

1000 
S270 IF L » 17 THEN C3 ■ 1 : GOTO 

1008 
3275 IF L - 26 THEN C3 = 1 : GOTO 

1000 

3230 IF L * 18 THEN C4 = 1: GOTO 

1000 

3285 IF L = 27 THEN C4 = 1 : GOTO 

1000 

3290 GOTO 1990 

'295 IF L = 16 OR L = 20 THEN 33 

05 
33O0 GOTO 1998 

3305 IF L = 16 AND K = THEM PRINT 
"CAN'T DOOR IS LOCKED FROM 
THER SIDE": GOTO 1190 
PRINT "OK": GOTO 1 190 
IF L r - THEN PRINT "MO 
T HERE": GOTO 1190 

IF R = 1 THEN PRINT "ALREA 
DY INFLATED": GOTO 1198 
PRINT "OK":P = II GOTO 1190 



IF M 



502O 

5030 

5O40 

5050 

5860 

5070 

5080 

5200 
5210 

5228 



"-" THEN 
"0" THEM 



RETURN 



3310 
3350 

3368 

3378 

3380 

3390 
3395 

340O 
T405 
3410 

3420 
J42E 

3430 
3440 
3450 
3460 

3470 



1488 

3485 
3490 
3500 
3510 
3520 
3530 
3540 
3550 
3568 
3570 
3530 
3590 
3600 
3610 
3628 
3630 
3648 

3658 



7660 

3300 
3810 



7900 



3918 

3950 

3960 

5000 



5288 
5290 



IF L S THEM FRIHT "NO 
T HERE": GOTO 1198 

FOR X = 1 TO 6 

IF 0(X> = O OR 0(X) * 8 THEN 
HE = HB ♦ 1 

NEXT X 

IF HB = 6 THEN 3420 

PRINT "NOT READY" I HB = 0: GOTO 5308 
1190 

FOP X - 1 TO 6 

IF 0(X> = 8 THEN 1=1-1 5310 
■ 40 

NEXT X 
H = l: 80T0 100O 5328 

IF H = THEN PRINT "HOT R 
EADY'i GOTO 1198 

IF L = 3 OR L = 36 THEN PRINT 5338 

'MEED TO GET IN FIRST": GOTO 
1190 

IF L = 34 THEN 3580 

IF L = 35 THEN 3578 

GOTO 1990 
2 = 13: Y = 5: GOSUB 6480 
Z = 8«Y « 11: GOSUB 6400 
Z = 31 Y = 17: GOSUB 6408 
Z « 8:Y » 23: GOSUB 6480 
Z = 13.-Y - 29: GOSUB 6408 

HOME 
L = 35: GOTO 1000 
Z = 13: Y = 29: GOSUB 6480 
Z = 8:Y = 23: GOSUB 6480 
Z * 3:Y = 17: GOSUB 6400 
Z = S:Y = 11: GOSUB 6400 
Z = 13:Y = 5: GOSUB 6400 

HOME 
L = 34: GOTO 1000 

IF 0(19) < > THEN PRINT 
"DON'T HAVE": GOTO 1190 

IF L > 27 AND L Z2 THEN PR INT 
"YOU QUICKLY GRAB IT BACK"': 

GOTO 1190 
0(19) ■ Ll I ■ I - H GOTO 18 

00 

IF L < > 2 THEN 1990 
FLASH : PRINT "YOU FELL OFF 
"I FOR X = 1 TO 3800: NEXT X 
: NORMAL :S = HL » 111 GOTO 

1000 

IF 0(9> = OR 0(9) = L THEM 
PRINT "SIGN SAYS: AN APPROPR 

IATE FLACE": GOTO 1190 
PRINT "CAN'T FIND": GOTO 11 

90 
IF 0(19) = THEN 3880 
PRINT "MEED SNORKEL": GOTO 

1190 
REM DIRECTION 



IF D* :::.L ' = "0" THEM FPIMT 
"OUT": RETURN 

IF D*(X,L) = "M" THEN PRINT 
•'NORTH": RETURN 

IF D*(X.L) = "E" THEN PRINT 
"EAST": RETURN 

IF M(X.L) ■ "8" THEN PRINT 
"SOUTH": RETURN 

IF D*(X»L) = "W" THEN PRINT 
"WEST": RETURN 

IF W(X.L) = "U" THEN PRINT 
"UP": RETURN 

IF D*(X,L) = "D" THEN PRINT 
"DOWN": RETURN 

REM OBJECTS 

IF 0(13) ■ AND L = 31 THEN 

PRINT "AN UNDERWATER TUNNEL 
"I RETURN 

IF L = 13 OR L = 14 OR L = 
17 OP L = 13 THEN PRINT "VE 
NT" 

IF L = 13 AND Ll = 1 THEN PRINT 
"VENT COVER": RETURN 

IF L = 14 AND C2 = 1 THEN PRINT 
■VENT COVER"! RETURN 

IF L ■ 17 HMD C3 ■ 1 THEN PRINT 
"VENT COVER"! RETURN 

IF L = 18 AND C4 = 1 THEN PRINT 
"VENT COVER": RETURN 

IF H = 1 AND L = 8 OR L = 3 
6 THEN PRINT "HOT AIR BALLC 
ON": RETURN 
2 = IMT (10 I RND ■ 1 ' ■■ + 1 

IF L = 6 AND Z = 1 THEM PRINT 

"THE BUTLER WITH TWO STICI 
OF DYNAMITE": RETURN 

IF L = 3 AND 2 = 3 THEM FRIMT 
"THE MAID WITH A PACK OF BLO 
ODHOUNDS": RETURN 

IF L = 7 AND 2=5 THEM FRIMT 
"THE GARDNER WITH A EULLDOZE 
R": RETURN 

IF L = 33 AND 2 5 THEN PR 
"A BAT PASSES CLOSE BY": RETURN 



IF L = 27 hMD 2 3 THEM PRINT 
U HAVE COBWEB IN YOUR HAI 
P": RETURN 
5340 IF L = 25 hMD 2 Z THEN F~ 
"a RODENT BRUSHES YOUR LEG": 
RETURN 
5350 IF L = 4 hMD 2=7 THEM PR! 
"A TuaD JUMPS ACROSS THE CPE 
EK"l RETURN 
5368 IF L = 28 hNC 0(14) = AND 
2 5 THEM PRINT "„ HUNGRY 
GULL CIRCLES OVERHEAD"! RETURN 



5230 
5240 
5250 
5268 

5278 



5378 IF L = 2 AND 2 = 6 THEM FPIMT 

"h PRIMATE VnTih'El FROM ABO'.' 

E": RETURN 
5398 RETURN 
6803 IF C* = "GET WELL" THEM I = 

01 PRINT "RECOVERED": 801 

190 
6020 GOTO 1990 
61O0 IF 0(19) = THEM PRINT "A 

LREADY HAVE OBJECT": GOTO 11 

-0 
6115 IF 0(19) - 40 AND 0(7) - THEN 
■ I*li 

00 
S120 IF 0< 19) = 40 Dt '- L "HEM 

0:l = l + i. 

00 

6130 IF 0(19) = L THE ■ 

:I = I - l: GOTO 1000 
6140 SOTO 1990 
6150 IF 0(13) ■ 3 THEN PRIN1 

LREADY HAVE"! GOTO 1190 
6160 IF 0(13) ■ 40 AMD L = 14 'HEN 
!> • 0: I - I ♦ ll SOT 

80 
6170 IF . -HEM 0< 13) =0 

1 1 ■ I ♦ 1 1 SOTO 1 000 
6180 GOTO 1990 



160 



CREATIVE COMPUTING 




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CIRCLE 271 ON READER SERVICE CARD 




THERE IS MORE THAN ONE WAY TO PLAY "WHAT IF" 





WHAT IF„ 

...suddenly your government andyour authority are at- 
tacked by a fanatical TERRORIST** group. Many lives 
and your leadership hinge on your decisive action. (And 
what if you were the terrorist?) 

...the success of failure of a nation-wide television 
NETWORK™ balances precariously at your fingertips. 
Are you shrewd enough to beat the ratings? 

...the WINDFALL™ profits of a turbulant oil market- 
place are yours to reap. Can you manipulate worker 
productivity, prices at the pump, a helpless public, and 
government intervention in your favor? 

...you awake in a bizarre island community whose 
hosts employ a sophisticated arsenal of brainwashing 
techniques to break you down. Can you escape to 
freedom, or will you remain forever the prisoner? 
Your computer is more than just an expensive 
calculator. 

Terrorist, Network, Windfall, and the prisoner... 
INTERACTIVE FANTASIES™ requiring 48K, Applesoft. 



[Hl(OTlK ™ Edu-Ware Services. Inc. 22222 Sherman Way Suite 102 Canoga Park, CA 91303 (213) 34M783 

Dealer inquiries welcome. 

CIRCLE 164 ON READER SERVICE CARD 



AUGUST 1981 



161 



Sourcebook 
of Ideas 



Many mathematics ideas can be better illustrated 
with a computer than with a text book. 




Consider Baseball cards. If there are 50 
cards In a set. how many packs of bubble 
gum must be purchased to obtain a complete 
set of players? Many students will guess 
over 1 million packs yet on average it's only 

9Zv< 

The formula to solve this problem is not 
easy. The computer simulation is Yet you 
as a teacher probably don t have time to 
devise programs to illustrate concepts like 
this. 

Between grades 1 and 1 2 there are 1 42 
mathematical concepts in which the com- 
puter can play an important role. Things 
like arithmetic practice. X-Y coordinates, 
proving geometic theorems, probability! 
compounding and computation of pi by 
inscribed polygons. 

Endorsed by NCTM 

The National Council of Teachers of 
Mathematics has strongly endorsed the use 
of computers in the classroom Unfortunately 
most textbooks have not yet responded to 
this endorsement and do not include pro- 
grams or computer teaching techniques 
You probably don t have the time to develop 
all these ideas either What to do? 

For the past six years. Creative Computing 
magazine has been running two or three 
articles per issue written by math teachers 
These are classroom proven, tested ideas 
complete with flowcharts, programs and 
sample runs. 

Teachers have been ordering back issues 
with those applications for years. However. 



many of these issues are now sold out or in 
very short supply. 

So we took the most popular 1 34 articles 
and applications and reprinted them in a 
giant 224-page book called Computers in 
Mathematics: A Sourcebook of Ideas. 

Ready-to use-material 

This book contains pragmatic, ready to 
use. classroom tested ideas on everything 
from simply binary counting to advanced 
techniques like multiple regression analysis 
and differential equations. 

The book includes many activities that 
don t require a computer. And if you're 
considering expanding your computer 
facilities, you II find a section on how to 
select a computer complete with an invalu- 
able microcomputer comparison chart. 

Another section presents over 250 
problems, puzzles, and programming ideas, 
more than are found in most "problem collec- 
tion'' books 

Computers in Mathematics: A Sourcebook 
of Ideas is edited by David Ahl. one of the 
pioneers in computer education and the 
founder of Creative Computing. 

The book is not cheap. It costs $15.95. 
However if you were to order just half of the 
back issues from which articles were drawn, 
they would cost you over $30. 

Satisfaction Guaranteed 

If you are teaching mathematics in any 
grade between 1 and 12, we re convinced 
you II find this book of tremendous value. If, 
after receiving it and using it for 30 days 
you do not agree, you may return it for a full 
refund plus your return postage. 

To order, send your check for $15.95 
plus $ 1 .00 postage and handling to Creative 
Computing Press. Morris Plains. NJ 07950. 
Visa, MasterCard, and American Express 
orders may be called in toll-free to 800- 
631-8112 (in NJ 201-540-0445). School 
purchase orders should add an additional 
$1 00 billing fee for a total of $17 95 

Don t put it off Order this valuable source- 
book today. 

creative 
corapafciisg 

Morris Plains. NJ 07950 
Toll-free 800-631 -81 12 

(InNJ 201-540-0445) 



Stonevllle Manor, continued. 



6200 REM SERVAL ATI 
6210 FLASH : PRINT "YOU *m[- XUST 
ENOUGH STRENGTH TO GET AUAY 

"i fop :: = ; 

: NORMAL : S = liL = til 

1000 

6300 IF V = o THEN PRINT "SEP'.'A 

OH'T LET VOL 1 ": GOTO 1190 
6310 L ■ 1?: . 
6400 REM BALLOON 
6410 HOME : VTAB 2 ' 
6420 PRINT TAB< Y>"- - -" 
6426 PRINT ThE< V - : ."- 

6430 PRINT TAB< Y - 2) "»=»===« 

6440 PRINT TAB( Y - I)"- 



6445 
6450 
6455 
6460 

6470 
6480 
6485 
6490 

65 00 



6510 
6550 
6560 

6570 

6575 

6580 
6585 

6590 

6595 

6600 

6605 
6610 

6620 

7000 

7010 

7030 

7040 
7050 

7055 
7060 

7070 

7075 
7080 



PRINT 
PRINT 
PRINT 
PRINT 
PRINT 
PRINT 



Y + 

Y + 

Y ♦ 

Y + 



1)".-. " 

IV. ." 

1)" " 

1 .."***" 

1>" " 

NEXT X 



= 1 TO 50: 



TAB< Y>" 
TAB< Y + 
TAB' 

TAB< 
TAB< 

FOR X = 1 TO 1000 
RETURN 

FOP :: = 1 TO 20:30 = PEEK 
C - 16336>: FOR 
NEXT V: NEXT X 
RETURN 
HOME 
PRINT : 
TO BUILD 
PRINT : 
ALLOON" 

PRINT 
CE" 
PRINT 
PRINT 
P CONTAINER 
PRINT TABC 
TWINE" 

PRINT TABC 
R LIGHTER" 

PRINT "BUILD BALLOON AT AN 
APPROPRIATE PLACE" 
VTAB 22 : HTAB <8> 
INPUT "PRESS RETURN TO CONT 
I HUE "iC$ 
GOTO 1000 
SAFE 

= THEN PRINT "CAN'T 
: GOTO 1190 

16 THEN FRINT 
: GOTO 1190 
COMBINATION LOCK" 
ENTER FIRST NUMBER 



PRINT TAB' 5 '"HOW 

A HOT AIR BALLOON" 

! PRINT TABC 8VI1 B 

TAB< S>"$2 HEAT SOUR 

TABC 3)" #3 FUEL" 
TAB< 8>"#4 GONDOLA 



8>"fS CABLE OR 
SV'#6 MATCHES 



N 



REM 

IF E = 

FIND": 

IF L ; 
OT HERE 

PRINT 

INPUT 
-"»F*<1 

GOSUB 6500 

IF F*(l m> THEN PRINT 
"NOT CORRECT": GOTO 1190 

INPUT "ENTER SECOND NUMBER 
— "IF*<2> 

GOSUB 6500 

IF FKl> + F*<2> S*( 1 • 

+ S»<2) THEN PRINT "NOT CO 
RRECT": GOTO 1190 

INPUT "ENTER LAST NUMBER — 
":F*< 3 i 

GOSUB 65O0 

IF F*<1> + Ft<2> + F*<3) < 
5* 1 ■ ♦ S*<2> ♦ S»<3) THEN 

PRINT "NOT CORRECT": GOTO 1 
190 
F = 1 

PRINT "CLICK 1 

...INSIDE IS A WILL": GOTO 1 
190 

HOME 

VTAB (6> 

7220 PRINT " ******************* 

**♦*♦* ************* " 
7225 PRINT " *": SPC< 36>:"*" 
7230 PRINT " ♦ wi 

LL ♦" 

7235 PRINT " * 

t" 



7090 
7095 

7100 



7105 
7110 



7200 
7210 



162 



CREATIVE COMPUTING 



7240 

7245 
725© 

7255 

7260 

7265 
7270 

7500 
7510 

7520 

7530 

7540 

"550 

7570 

"530 

-5 ?0 

-600 

7-605 

7610 

7615 

7620 

"625 

-640 

-670 
-6.50 



3010 
3020 
303O 
3040 
3050 

3060 



STONE. LE 
ALL MY WORLDLY '" 
PRINT " + POSSESSIONS TO WH 
OMEVER OPENS THIS * 
PRINT " * SAFE. 

♦ " 

PRINT " ♦": SPC-: 56>l"*" 
PRINT " ******************* 
lent****************** 
PR I NT 

PRINT •■ :ONGRATU 

LATIONS "I END 

HOME ■' PRINT 

PRINT "WELCOME TO STONEVILL 
E.YOU HAVE RECENTLY" 
PRINT "LEARNED THAT HEALTHY 
MR. STONE DIED AND" 
PRINT "RUMOR HAS IT THAT TH 
IS ECCENTRIC MISER" 

PRINT "HAS LEFT HIS ENTIRE 
ESTATE TO WHOMEVER" 

PRINT "FINDS AND OPENS HIS 
SAFE. ": PRINT 

PRINT "TO PLAY. YOU MUST MAN 
IPULATE OBJECTS AND" 

PRINT "EXPLORE YOUR SUPROUN 
DINGS BY USING TWO* 

PRINT "WORD COMMANDS. FOR EX 
AMPLE, 'GET BASKET'" 
PRINT "OR "GO SOUTH'. TO SPE 

DIRECTIONAL" 
PRINT "MOVEMENT. 'GO' COMMAN 
DS HAY EE SHORTENED" 
PRINT "TO INCLUDE ONE LETTE 

tCH AS 'GO 3'.": PI \ \ 
PRINT "THE COMMAND 'SAVE 6A 
ME' WILL PRESERVE" 
PRINT "YOUR PROGRESS FOR 

_ATE* TIME" 
PR Itr "OR IF YOU F REFER TO 

: END 'HE GAME" 
PRINT "THEN ENTER 'END' GAME 
'.AND. IF NEEDED," 
PRINT "CLEAR SCREEN' WILL 
RESET YOUR LOCATION. " 
VTAB 22 •' HTAB 
INPUT "PRESS RETURN TO C 
INUE"»C*i RET 

DATA "BALLOON", "FALLEN WEAT 
HEP BALLOON", 3. "STOVE". "J 

3t BURNING STOVE". 1,"BAS 
KET", "LARGE WICKER E'ASKE™.! 
2 
DATA "LOGS". "LOGS". 40. "1 
E"."ROLL 3F TWINE". 17. "MATCH 
ES". MATCHES"- 15 
DATA "BAG" . "BURLAP BAG " .18. 
" PmFT " . " I NFLATABLE RAFT" . 1 » " 

sign". "sign*. 8 

data "net". "fish net",7."sh 
oes" • "jogging 3h0es". 10. "axe 
","axe",10 

data "ma im mask ".40, 
"trout". "tro joblet". 

30BLET".19 
DATA "BOTTLE". "EMPTY BOTTLE 
OF CHABLIS".K,"BOOI "."( 
", 14, "FICTURE". "PICTURE " 

p DAtP J !nC#EL" ■ "SNORKEL" ■ 40 
,-Mfl 'ILLE MANOR"- 

J, "MANOR". "STONEVILLE MAI 

3070 DATA "SHACI iBANDONED 

ABLE". 37. "CREDENZA" 
CREDENZA", 14 
3030 DATA "SAFE". "SAFE" 
". "CASE OF CHABI 

S"."Tp E r 

'DOOR"."D 
'. "DOOR", 16. 'SER 1 
OPTED 3ERVAL „„ lM 

r«, "GENERAL *TuPE 
» , 9, ■ 1 " J 

F !ThL".? 
S118 DATA "IN THE COURTYARD" 
kCh" ."IN A MEA 
H3 a SLIPPERY CREE 

- LAI E". "IN A 
BARREN FIELC "." 
: ." 

AUGUST 1981 



,40." 

.IS. "TREE 

IMP 



120 DATa "hT THE EDGE OF A 0ORG 

wt-m&w umpmninvt 

HE HOSPITAL". "IN THE FOYER". 
"IN THE PARI 
3130 DATA "IN THE STUDY". "IN 

ORIEL". "IN THE GALLERY". "IN 
THE ATRIUM". "IN THE 

E CELLAR"- "IN TH 

E EA :ELL 

3140 ijMlTA"HrJlTAlllH6UTCET0*(NATaf«J-B 

"AT m F £ PUCI" • " H ' 

(JuBflTiBTTiA THC 

B1S0 DATA "•■ rLET IN T 

.;,--. "A* AN OUTLET I 
CT"."OH THE LAKE". "IN THE "- 1 
UTHEF'l BAY", "UNDER THE 
CE OF THE LAKE". "UNDER THE S 
hCE OF THE LAKE" 



3160 DATA "ALONG AN UNDERGROUND 
P I VER " • " I NS I DE a C A'.'ERN " . " I N 
a HOT AIR BALLOON". 'IN A Ho 
T AIR BALLOON". "ON TOP OF A 
PLATEAU". "INSIDE T HE SHAI 
8170 DATA '".i".:' "S".4,"-".0."E" 
. 1. 2»"E".4." 

- •• . 

', ;.-E".7."-" 
-".0 
DATA "W".7,*- h .O," 

-",£ 

. U."S%44. 
"S'M7,"W",13,"E".15,"S".16 

3198 DATA "W".14,"-".O. ,, - ,, .0. "N" 
,14."W",17."-",0,"O , M,"N".l 

3."E". 16, "E",19,"-",0>"-",0' 
"W" .13- "U" , 20. "-",0. "D". 19. " 
-",0,"-",0. "0".13,"S",22,"-" 
,0, "N",21,"E",23,"-",0 



computer slops of the month 




The Program Store 



The widespread use of computers in today s society has created numerous 
openings of computer stores over this country. Creative Computing -would 
like to recognize one of these stores for their service and dedication to their 
customers and the computer industry This month, we are spotlighting The 
Program Store in Washington, DC. 

While tourists flock to the national monuments, computer enthusiasts 
visiting Washington, DC. have an additional stop: The Program Store 
Customers delight to the assemblage of more than 1000 programs for TRS- 
80. Atari, and Apple computers, perhaps the largest selection of programs 
to be found anywhere. 

Beginning as a mail-order outlet in 1978. the Washington store was 
opened a year later, followed by a Baltimore. MD location in late 1980 
Computers are available to try out the programs before purchasing them, 
and the stores additionally carry Atari computers and a selection of hardware 
peripherals for popular microcomputers .-—.,. 

'We are a people-oriented store, where our customers feel at home says 
president Ray Daly Perhaps this attitude is the reason for the demand for 
more Program Stores Vice president Janine Perky says, We have recently 
begun franchising operations in order to fill the needs of other cities for our 
kind of stores. 

The Program Store has locations at the Tenly Mall, 4200 Wisconsin 
Avenue N IW„ Washington. DC. 20016. and W Bell Plaza. 6600 Security 
Blvd.. Baltimore. MD 21207 The stores toll-free phone number is 800- 
424-2738. . 



163 







Get 12 issues of 



I 



Some things are still cheaper by the dozen. 

When you subscribe to Creative Computing, you get 12 issues for just $20. The same 12 
issues would cost you $30 at the newsstand. 

T^Jh^^i^ 1 ' ^ ?° mP o'f,£ aU year long and save $1 ° at the sa ™ time. 
2m ^nn/^n ^""^ fr ° m 9 AM to 6 PM 800-631-8112. In New Jersey, call 

ul^^'^TS^SS^^ 99 Morris PIains ' NJ 0795 °- We accept Visa - 

h^H^S WnP "' i>W ? thG l6ading ma « azine of smaI1 computer apphcations and software. It 
has in-depth reviews of new systems, peripherals and software. Also articles for both 

nSwJT an n 6Xper , tS ; columns about popular computers, programming techniques and new 
products; and complete program listings for your computer 

thp rZ It !?** SayS ' " J read Cr T ive Com P utin 8 not only for information about how to make 
the most of my own equipment but to keep an eye on how the whole field is emerging " 

Z,^ n ° )01 a ° Ve J 90,000 subscribers an <* save money at the same time? If you?e clever 
enough to order a dozen. ^^^^ 










Stoneville Manor, c 



S200 DATA "W">22,'N%24 : "S"-,2S ;i 
»0"Fl4."8".23."-".e»"N .23. 
«".26."-".e."0".17»"0"'27."E 

-.2S,»0-,18,"U".26 ; -;".e. 0" 

,5,"S".29-"-"-0' N ",28."- '0 

3210 'DATA "U"i?8."S".Sl.;-";e," 

»,33."-".ei."E".32,"-".0.":";, 

e ^o-,8. ---.»•";■ i«;"2 VS'i 

-»,e. "-"-0> ■-"»•■ "-"»•»- > 

,"0"-36, "-".0,"-"-0 



ftMfl DAT* "VENT 18 COVERED". "SON 
°" ETHINS IS TO BI8". "INSIDE IS 

ft NOTE WITH THE NUMBER " 
3230 DATA 13.14.17.18.21.24.26. 



8388 
3318 

8338 
374? 
3358 
3388 

S370 

3390 
3395 



'REM RETRIEVE 

D* = CHP* C4) 
PRINT D*;"OPEN hhME 
PRINT D*?"READ GAME" 
INPUT L.U.S.I.F.H.R.K.E.V 

ISKt Sc»?:S<iU«>. 

1 :■ . 3* 

FOR X = 1 TO 3" 
INPUT 0<X> 

PRIHT X D«»"CL06,= 6«ME": RETURN 



3450 PRINT N»C1>: PRINT N«<2>! 

3460 PRINT S»<1>: PRINT S*<2>: 

St 

3470 FOP : : = 1 TO 33 

3480 PRINT OCX) 

9498 NE: 

3495 PRINT D*; "CLOSE GAME' 

S500 HOME : END 



PRINT 



□ 



REM SAVE 
D* = CHP* 4) 
PRINT D*»"OPEN GAME" 
FRINT Df: "WRITE GAME" 
PRINT L: PRINT Ml PRINT 
T • PC T MT F 
PRINT HI PRINT Rl PRINT Kl 
c« PPTMT " 

PRINT Cli PRINT C2: PRINT C 
3: FRINT C4 



PRINT 
FRINT 





^^ 



Relax. Hal li won* replace you. its not umple 

enough. " 



PET/CBM 
APPLE 



STOP PLAYING GAMES l R T s H f » Mode ' & ,ll) 



^Pv 



SBtJSsoTHORsTOcES with ANY COMPU 

I SCIENTIFICALLY DERIVEO SYSTEM really .rorks^TV 
SUIion WLKY ol Louisville Kentucky used this .syletr. 
10 predict the odds ol me 1980 Kentucky DetDy See 
the Wall Street Journal Uune 6 19801 ari,cle on 

2n noises m each race COMPUTER POWER gives you the advantage' 

■ YOIJGET 1) TRS-80 (Level III or Apple Cassette 

■ yuu<*' ■ * BAS | C p, og ,am tor use *rth any computer 
2 3 mstruc'ionson >-ow to get the needed data Irom the Daily Racing Form 
41 Tips on using the odds generated by the program 
5) Sample lorm to simplily entering data lor each race 

MAIL COUPON OH CALL TOOAV — — 

3Q COMPANY. INC. OEPT. CC (503) 357-9889 

RT 3. BOX 28A, GASTON, OR 97119 

Yes I wanl to use my computer lor FUN and PROFIT Please send me _ programs 
at $24 95 tie* J£ 

[nml , IPS 80 Cassette 'Apple Cassette Ft T/CBM Cassette «• 

Enclosed is check or money order Master Charge Visa 




TAMPICO LABS, INC. 

P.O.BOX 1000 

Across from Ramada Inn 

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CALL 90 4-243-8565 

'CIRCLE 218 ON READER SERVICb CARD 




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.E 222 ON READER SERVICE CARD 




ucf s . . . ae w products . . . new 




TERMINALS & I/O 



12-VOLT PRINTER 



80-COLUMN PRINTER 

Microtek. Inc. announces an 80-column 
dot matrix printer, the Bytewriter-I. The 
printer accepts single sheet or roll paper 
up to 8 1/2" wide and prints at 60 lines 
per minute using a 7 x 7 dot matrix. 





Syntest Corporation announces the SP- 
314 dot matrix alphanumeric printer which 
features 12-volt D.C. operation allowing 
complete independence from power 
lines. 

Other features of the SP-314 include: 
buffered 40-column impact printing. RS- 
232 serial and parallel inputs, crystal 
controlled baud rate, %-character ASCII 
set plus double width, and a self test routine 
In addition, the unit includes graphics 
capabilities for special printer applications. 

«.^ ,eSt - m Millha m St.. Marlboro. MA 
01752. (617) 481-7827. 

CIRCLE 35t ON READER SERVICE CARD 



The Bytewriter-1 interface is similar to 
a Centronics parallel interface, and has 
been designed specifically to operate with 
the Apple II. the Atari 400/800. and all 
models of the TRS-80. $299. 

Microtek. Inc.. 9514 Chesapeake Dr 
San Diego. CA 92123. (714) 278-0633 

CIRCLE 352 ON READER SERVICE CARD 



MEMORY 

16K RAM CARD FOR APPLE 

™aWa w ^° P haS annou "ced the 
13I0K, KAM Card to increase Apple II 



memory. With 48K bytes of RAM already 
in place, the card increases capacity to 

The Card is compatible with Pascal 
CP/M DOS 3.3. Cobol. Fortran. VisiS!' 
Pilot. Integer Basic. Applesoft Basic and 

H $19? " CUrren " y used wi,n A PP' e 
Computer Stop. 2545 W. 237th St.. Suite 
L. Torrance. CA 90505. (213) 539-7670 

CIRCLE 353 ON READER SERVICE CARD 

MEMORY SYSTEM FOR 
ATARI 800 

Axlon Incorporated has introduced the 
Axlon 256 memory system, which increases 
the storage capacity of the Atari 800 
computer from 48K to 256K of RAM. 

The product functions as a very fast 
<Jsk. It is plug compatible with the Atari 

The system comes with two 32K «. 
CRAM modules and additional moduie 
can be added until the full 256K capacity 



166 



CREATIVE COMPUTING 



WHEN YOUR NUMBER 
IS UP, CALL OURS. 






1 -800-321 -M ETA 



IN OHIO, (216) 289-META 



When you are weary of the "NEVER UNDERSOLD" dealers, when you are 
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CIRCLE 228 ON READER SERVICE CARD 



New Products, continued... 

is achieved. Atari RAM modules can also 
be used in the Axlon system. 

The standard system, with 64K of RAM. 
has a suggested retail price of $895. 

Axlon Inc.. 170 N. Wolfe Rd.. Sunnyvale. 
CA 94086. (408) 730-0216. 

CIRCLE 354 ON READER SERVICE CARD 



PERIPHERALS 



UPGRADE FOR ATARI VCS 

Computer Magic. Inc. announces the 
MagiCard. a plug-in module for the Atari 
Video Computer System. The MagiCard 
is said to allow Atari VCS owners with 
keyboard controllers to upgrade the game 
to a self-contained computer. 

The MagiCard contains IK bytes of 
RAM and a 2K byte ROM monitor whose 
capabilities include commands for exam- 
ining and depositing into memory, disas- 
sembling 6502 microprocessor programs, 
and running user-written programs. Mon- 
itor subroutines to display text or memory- 
mapped color graphics on a TV screen 
are accessible to the user. $49.88. 

Computer Magic. Inc.. P.O. Box 3383P. 
Fox Valley Center. Aurora. IL 60505. 

CIRCLE 355 ON READER SERVICE CARD 



A 



DIRECT-CONNECT MODEM 
FOR APPLE 




Standard features include originate/ 
answer, programmable word length, parity, 
number of stop bits, and full/half duplex. 
Optional at extra cost are auto-dial and 
auto-answer functions. $289.95. 

ESI Lynx. 123 Locust St.. Lancaster. 
PA 17602. (717) 291-1116. 

CIRCLE 356 ON READER SERVICE CARD 



PERCUSSION SYNTHESIZER 



A direct-connect telephone modem for 
use with Apple II and Apple II Plus 
microcomputers has been introduced by 
ESI Lynx. 





i - ERADICATE 



UNCREATIVE 

COMPUTING 

subscribe! 



The Rhythm Box is a peripheral that 
synthesizes the sounds of seven different 
percussion instruments including bass 
drum, wood block, snare drum, short 
cymbals, long cymbals, hand-clap, and 
tom-tom. It is programmed in Level II 
Basic or assembly language; a single 
instruction generates any combination of 



do/ bo// 

f DISK COMMAND EDITOR 



DOS BOSS is Beagle Bros new Apple utility package that will let you in- 
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Printers, software, hardware & accessories for: 

APPLE, TRS 80 & OTHER COMPUTERS 

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168 



CIRCLE 170 ON READER SERVICE CARD 

CREATIVE COMPUTING 



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5V*" DRIVES 

• PATINUD SKWOMND POSlltOMf* 

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^^M a s"voi£ *ca 

MPI51 -: 239.95 MPI91 335.95 

MPI52. 335.95 MPI92 »-~ 475.95 

TANDEM TM100-1 .-..■■ ' t«95 

TANDEM TM100-2 DUAL HEAD 259M 

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SANTA ANA, CA 92705 



APPLE" 40 CHARACTER 
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Breakthrough In 
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Subsystem For Your Apple II 



Vista 



• UP TO 40 CHARACTER TYPE-AHEAD CAPABILITY. 
JeNTER COMMANDS OR DATA WHILE YO<JRAPPLE 

IS PROCESSING PREVIOUS INSTRUCTIONS. 

• COMPATIBLE WITH ALL APPLE' COMPUTERS. 

. rN E C?urs%rp D L^ F ;N W ST R RUCT,ONS FOR OU.CK 

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REQUIRED. 

CONTACT YOUR LOCAL DEALER OR 

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nSJ!Sp~<! DMA »■"•'" ol d... 1 1 m.cfoMCO~l OyWI 

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• 2K ■ 8 PROM contain* Autotxxrt Iwnclioni and lit 
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coVnpat.b.l.ly ».m Apon DOS 3 2 3 3 

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ASM - 595 .00 

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Advanced Computer 
Products System 
Packege Special 




|p o bi I7J21. Irian. C» tfiu 
Diraci Orasf Uait: 

i;i4liSHII3linOI»5*-»73OIIO0lt54«741 

FOB INTEKIMTIOIlAl OnOIRS 

1310 E. Edl.itr (7111 K3-0M4 

Stall A.1 CA 92705 TaTJ. 910-595-1565 



CIRCLE 146 ON REAOER SERVICE CARD 



New Products, continued... 

percussion sounds plus a loudness control 
for rhythmic emphasis. 

The Rhythm Box is available with two 
interface options: Model RBX-T ($149) 
for the Model I Level II TRS-80 has a 40- 
pin ribbon cable that plugs into the 
keyboard or EI bus extension connector 
The Model RBX-S ($179) is for use on all 
other computers (S-100. PET. Apple, etc.). 
and connects with two wires to any 
standard 9600 baud serial interface using 
either RS-232 or 20ma current loop 
levels. 

Newtech Computer Systems. Inc.. 230 
Clinton St.. Brooklyn. NY 11201 (212) 
625-6220. ' 

CIRCLE 357 ON READER SERVICE CARO 



TEKTRONIX EMULATOR 
FOR S-100 

A graphics interface and software pack- 
age available from Cambridge Develop- 
ment laboratory enables S-100 computers 
to emulate a Tektronix 4010 series terminal 
The Raster Scan Tektronix Emulator 
provides excellent resolution (640 x 512) 
raster graphics in black and white, gray 
tones, or color. All hardware is S-100 bus 
compatible. 



"Ne'er look for the birds of this year in 
the nests of the last." 

Cervantes 




do you have 
a hard time tearing 
yourself away... 




. . from endless tax tables and 

computations every time you 

run your payroll? 



Look at these other powerful features! 



ES2SEZZ* ""■"»"-—"- Waslw^on d.c~5, 
tormula. are bulk In. no meuy entry from ta» table, required 

• WAOTY of 300 employee,. 1 5 Dn^on^Store, In mu«pte 
£*« any late Up to 30 addMond W defined *duoKn 

• •^Sp^ ( ro«cr«^checkre 9 i^,W2forrn*ae.urnn w 
UMge Information all l„ the tin* * take, your pnnte, to pnnt! 

• ™^«>ORT*„ you rn^ you, punrf^. Hotline lo, 
technical a««ance Payro. «» UDdott sefvlce t<) 

coat (free (or the Arc yea,,. Your »y*em neve, become, obwlete! 



6r0derbund Software 



Consider the fast and versatile 
alternative. PAYROLL from 

D »<Jl < ? dOTbund So**"* » written in 

PASCAL and assembly language so it 

runs many times faster than Basic yet it 

requires no language card or other special 

hardware! PAYROLL will run on any 48K 

Apple II with DOS 3.3 and two disk drives 



Coming aoon PASCAL General Ledge, 

Account. Receivable 
_ Accounts Payable 

Apple In a trademark of Apple Computer Company 



Box 3266. Eugene. Oregon 97403 (503) 343-9094 
CIRCLE 129 ON READER SERVICE CARD 

170 



Software is CP/M compatible, offering 
an unlimited number of character sets 
selective erase, and color selection. Com- 
patible monitors, light pen. and graphical 
Basic are available as other hardware 
options. 

Cambridge Development Laboratory 
36 Pleasant St.. Watertown. MA 02172 
CIRCLE 358 ON READER SERVICE CARD 



DIRECT/ACOUSTICALLY 
COUPLED MODEM 




Lexicon Corporation announces a 300 
bps modem, the LEX- 12. for the personal 
computer and terminal markets. 

The LEX- 12 allows direct coupling at 
the telephone handset jack, direct coupling 
to the phone line or acoustic coupling 
thru the telephone handset. 

The 300 baud director acoustically 
coupled, full-duplex modem has originate 
or answer capability switch selectable. The 
RS-232 interface of the LEX- 12 makes it 
compatible with most terminals, and small 
computers. $199. 

Lexicon Corporation. 8355 Executive 
Center Dr.. Miami. FL 33166. 

CIRCLE 3S9 ON READER SERVICE CARD 

DIRECT CONNECT MODEM 

Bizcomp Corporation introduces the 
Model 1084 Intelligent VersaModem 
specifically designed for use with Apple 
Radio Shack. Commodore. Atari and many 
other computers. 



CREATIVE COMPUTING 




compi 
products, 



inc. 



NEW LOCATION 

1198 E. Willow Street 

Signal Hill, CA 90806 

Toil pm (800) 421-7701 outside cm 

(21 3) 595-6431 inside cm. 



MICROBYTE 32K STATIC RAM BOARD 

|$500 09 

•Fully S100 bus 
compatible 
IMSAI. SOL. 
ALTAIR. 
ALPHA MICRO 

•Uses Intel low power 214114 4K*1 Static RAM 

•2 MHz or 4 MH; operation 

•Each 4K bank addressable to any 4K slot witriin a 64K boundary 

•4K hardware or sottware selectable 

•Win operate wiin or wiinoul Iron! panel 

•Low power consumption 800mA 

•Fully warranted lor 120 days Irom gate ol smpment 





Console has non-glare 12 inch 
diagonal display screen Bright 
ness control enhances clarity 
Detached typewriter style key- 
board designed tor optimum 
operator comlort and usability 



AMPEX 

DIALOGUE 80 

CRT VIDEO TERMINAL 

Reg. Price 
$995. 00 

OUR LOW ASAP 
DISCOUNT PRICE 

00 



4116's 

(200 NS.) 
Apple. TRS40, Heath etc 

8 for $20.00 

1649 $235 

50-99 $2.25 

100 Up $2.15 



$945. 



2114L-2 



(200 ns) Low-Power 

STATIC RAM 

1-16 $3.05 

17-49 $2.95 

50-99 $2.85 

100 Up $2.70 



INTRODUCING 

asap's 

atari 800 

Computer System 

16K RAM MODULE 

$7995 

I YEAR WARRANTY 
PARTS AND LABOR 



TELEVIDEO 



CRT/TERMINALS 

MODEL # PRICE 

749.00 

769.00 

825.00 

825.00 



ORDERING INFO 



Name, address, phone 

Ship by UPS or Mall 

Shipping Chrg. Add $2.50 up to 

1 Id. -Call tor larger shipments 

Freight. U.S. Mall Add St. SO 



arger shipments 
it. U.S. Mall Ado St" 
U.S. Only up to 2 lbs. 



TVI912B 

TVI912C 
TVI 920B 
TV I 920C 
TVI 950C 

IN STOCK 
90 DAY WARRANTY 



$ 
$ 
$ 
$ 
$1025.00 



2708's 

1Kx8EPROM 
450 ns 

$4.75 ea. 

OR 
8/S36.00 



HITACHI 

(MONITORS) 



VM910 
VM906 



SIZE 

9' B&W 
9 B&W 
VM129 12" B&W 
VMI7 17 B&W 
CM13L 13' Color 



PRICE 

S210O0 
$265 00 
$340 00 
$360 00 

$376 00 



QUME DT-8 
8" FLOPPY 
DISK DRIVE 



•Dou ble Sided/Single Double 

Density 
•IBM compaiible/1 2 Mbytes 

per Disk 
•Fasl -3 mi Track 10 Track 
• 1M Tracks/Daisy Cham 4 

Drives 
•ISO Standard Write Protect 
•Programmable Door Lock 

CALL fOR PRICE A DELIVERY 



2716's 



2K x 8 EPROM 
5 VOLT/450 ns 

$6.95 ea. 

FULLY GUARANTEED 



TERMS 

We Accept Cash, Check. Money 

Orders. Visa & Master Charge 

(U.S. Funds Only) 

Tax: 6% Calif. Res. 

COD's & Terms Available on 

Approval (School PO's Accepted) 

($25.00 Minimum Order) 



THE EPSON MX-80 

80 COLUMN DOT MATRIX PRINTERS 




CALL FOR PRICE 

AND DELIVERY UmiTim -=x* 

'Optional interfaces Available *.*» *.*• < — 



€ 



( eiliforniei 

< "in [liitrr 

Svvtcim 



MODEL 7728A 

CENTRONICS PRINTER 
INTERFACE FOR APPLE 



m iBi«i , li siej»sjjejjic« ^ «il»J«> 




lie " mm ■»■ » — » p«e>i tne> Imm * «• 
■aJM - m «*MM m«a« MM •*■» «**■* 

illS s 95 



00 



'Optional cables available 



SHUGART 
SA801R 

8" Sgl/Sided. Sgl/Dbi 
Density Floppy Disk Drive 

CALL FOR PRICE 
& DELIVERY 



100 PIN IMSAI 

Gold/S-100 Soldertail 
Connectors 

'2.40 each 
or 

10/$2.25each 



CIRCLE 109 ON READER SERVICE CARD 




AUGUST 1981 



171 



CIRCLE 132 ON READER SERVICE CARD 



New Products, continued. 




The VersaModem allows automatic 
dialing and auto-answer capability con- 
trolled through an RS-232 interface. Its 
Code-Multiplexed Design allows dialing 
functions to be implemented in high level 
languages such as Basic or Cobol. $299. 

Bizcomp Corporation. P.O. Box 7498, 
Menlo Park. CA 94025. (415) 966-1545. 

CIRCLE 360 ON READER SERVICE CARD 



DISK & TAPE 
SYSTEMS 



DOUBLE DENSITY DISK 
CONTROLLER FOR 
HEATH /ZENITH 89 

Magnolia Microsystems has released a 
double density disk controller for the 
Heath/Zenith 89 computer which supports 
up to four 8" disk drives and four 5" disk 
drives. These supplement the three 5" 
drives supported by the existing Heath/ 
Zenith controller. 

^^ 



COMPUTERS BY MAIL 

P Box 1805 Hawthorne. CA 90250 



PRINTER AND INTERFACES 

ANA0EX 9501 132 COL 
ANADEX 9500 132 COL 
EPSON MX80 PIN FEED 
EPSON MX80 TRACTOR/FRICTION 
EPSON MX70 PIN FEED 
EPSON PARALLEL CARD 
EPSON SERIAL ADAPTOR BOARD 
EPSON CARTRIDGE RIBBON 
EPSON PARALLEL INTERFACE CABLE 
CALIFORNIA COMPUTER SYSTEMS 
ASYNCHRONOUS SERIAL 
SYNCHRONOUS SERIAL 
PARALLEL 
CENTRONICS 7721 W/O CABLE 
CENTRONICS 7728 W/O CABLE 
MONITORS 
SANYO 9 B I W 
SANYO 12 HI RES BSW 
SANYO 13 COLOR 
MODEMS 

HAYES MICROMODEM II (APPLE II) 
HAYES MICROMODEM 100 (Si 001 
HAYES SMARTMODEM (RS 232> 
SOUTHEASTERN DATA CAPTURE 4 
DISK DRIVES 

MICRO SCI 40 TRACK W/CONT 
MICRO SCI 70 TRACK W/CONT 
APPLE DISC II W'CONTROLLER 
♦ DOS 3 3 

EDUCATIONAL SOFTWARE 

EOUWARE 

STATISTICS 

EDU PAK I 

STORY TELLER 

ALGEBRA I 

UNI SOLVE 

COMPU MATH ARITH SKILL 

COMPU MATH FRACTIONS 

COMPU MATH DECIMALS 

COMPU SPELL (REQ DATA DISK) 

SPACE 

SPACE II 

NETWORK 

TERRORIST 

WINDFALL 

PRISONER 
MICROSOFT TYPING TUTOR 
SUB LOQIC FLIGHT SIMULATOR 
SYNERGESTIC STAR 
GAZERS GUIDE 

ENTERTAINMENT SOFTWARE 
HAYDEN SARGON II 
INNOVATIVE DESIGN POOL 1 5 
MICROSOFT ADVENTURE 

OLYMPIC DECATHALON 
MUSE ABM 

PERSONAL SOFTWARE ZORK 
USA SOFTWARE SPACE RAIDERS 
TEMPLE OF APSHAI 
HELLFIRE WARRIOR 
STAR WARRIOR 
TUES MORN QUARTERBACK 
GALAXY WARS 
ALIEN RAIN (GALAXIANI 
SNOGGLE (PUCKMAN) 
3D GRAPHICS 



1395 00 

1395 00 

519 00 

61900 

405 00 

65 95 

6195 

1300 

21 95 

125 95 
139 95 
95 95 
95 95 
95 95 

169 00 
255 00 
435 00 

299 00 

325 00 

245 00 

44 95 

460 00 
575 00 



24 95 
32 95 
16 95 
32 95 
19 95 
32 95 
32 95 
32 95 
24 95 
24 95 
19 95 
16 95 
24 95 
16 95 

24 95 
16 95 
29 95 

25 95 



27 50 
29 96 
25 95 
19 95 
1995 
29 95 
24 95 
32 95 
32 95 
32 95 
24 95 
1995 
1995 
19 95 
32 95 



N 

E 
W 



MUSE ROBOT WARS 
AUTOMATED SIMULATIONS 
CRUSH . CRUMBLE STOMP 
DRAGON EYE 
WORD STAR 
SPECIAL MO CARD 



32 95 

24.95 

19 »S 

249.95 

259 95 



MICROSOFT 18K EXPANSION BO 149.95 



APPLEOIDS 

H/R *1 MYSTERY HOUSE 

H/R -2 WIZAROS/PRINCES 

H/R FOOTBALL 

MISSILE 0EFENSE 

HI-RES SOCCER 

WARP FACTOR 

ACCESSORIES 

K ♦ D COOLING FAN 

TO. JOYSTIX 

GAME PADDLES 
MISC HARDWARE 
"CPS MULTI FUNCTION CARD 

APPLE CLOCK (W/MC1 0012 P) 

1000.000 DAY CLOCK 

(W/MCI0012P) 

SUPERTALKER 

ROMPLUS 4 (NO ROM 

PROGRAMSl 

ROMWRITER 

INTROUX 10 CONTROLLER 

CARD ONLY 

MUSIC SYSTEM W/SOFTWARE 

A/D D'A W/O CABLE 

1/0 CABLE ASSEMBLY 
M . R SUPER SUPERTERM 
APPLE II 80 COL VIDEO CARO 
VIDEX VIDEOTERM CARD (80 COLI 

SWITCHPLATE 

KEYBOARD DISPLAY 
ENHANCER 
CALIFORNIA COMPUTER SYSTEM 

CALENDER/CLOCK MODULE 

BUSINESS SOFTWARE 
CONTINENTAL SOFTWARE 

HOME MONEY MINDER 

CPA I GENERAL LEDGER 

CPA II ACCTS RECEIVABLE 

CPA III ACCTS PAYABLE 

CPA IV PAYROLL 
MUSE SUPER TEXT II 

ADDRESS BOOK 

FORM LETTER MODULE 

DATA PLOT 
PERSONAL SOFTWARE 

DESK TOP PLAN II 

CCA DATA MGT 

VISICALC 33 
PROGRAMMA INTERNATIONAL 

APPLE PI (APPLE) 

APPLE P1 (SUPERTERM) 

APPLE PI (VIDEX) 

APPLE PI (OTHER 80) 
STONEWARE OB MASTER (NEW) 
SYNERGESTIC MAILING LIST DATA BASE 

MODIFIABLE DATABASE 



24 95 
1995 
2450 
29 95 
24 95 
32 95 
48 95 

39 95 
44 95 
32 95 

175 00 
239 95 

31900 
254 00 

132 00 
150 00 

170 00 

450 00 

295 00 

42 95 

24 95 

31500 

295 00 

15 95 

99 95 

105.95 



28 95 
145 00 
14500 
14500 
14500 
11500 
3995 
8500 
4895 

16900 

72 95 

11995 

10595 
105 95 
105 95 
105 95 
15995 
32 95 
64 00 



ADD 3°. FOR FREIGHT/HANDLING 

CALIFORNIA ADO 6% SALES TAX 

PLEASE NO CODS ALL MFGS WARRANTIES 

APPLY ALLOW 2 WEEKS FOR CHECKS TO 

CLEAR PLEASE INCLUDE NAME COMPLETE 

ADDRESS AND TELEPHONE NUMBER PRICES 

SUBJECT TO CHANGE ALL PRODUCTS IN 

STOCK AS OF PRESS DATE CBM 

PO BOX 1805 HAWTHORNE CA 90250 

(213) 533-4071 



CIRCLE 108 ON READER SERVICE CARD 



172 



A 5" double-sided. % TPI drive holds 
up to 700 KBytes, while an 8" double- 
sided drive holds over 1 .2 MBytes. Four 
of each gives the 89 user on-line access to 
7.6 MBytes of information with the inter- 
changeability of floppies. $595. 

Magnolia Microsystems. Inc.. 2812 
Thorndyke Ave. West. Seattle. WA 98199. 
(206) 285-7266 or (800> 426-2841. 

CIRCLE 361 ON READER SERVICE CARO 

BOOKS AND 
BOOKLETS 

SOURCE BOOK FOR 
HEATH/ZENITH 

The Information Center announces The 
Information Center Sourcebook, a buyer's 
guide for users of Heath/Zenith computer 
systems. 

The Sourcebook features separate sec- 
tions for hardware, software, printed 
matter, and business applications software, 
as well as listings of dealers and service 
centers. $20. 

The Information Center. 642-A West 
Rhapsody. San Antonio, TX 78216. (512) 
340-1561. 

SOFTWARE BUYER'S GUIDE 

Lifeboat Associates had released a 
buyer's guide and catalog. The 35-page 
catalog lists over 50 media formats. CP/M 
compatible disk operating systems, hard 
disk integration modules, system tools, 
telecommunications, languages, language 
and application tools, word processing 
systems and aids. Also listed are data 
management systems, general purpose 
applications, mail list systems, financial 
accounting packages, numerical problem- 
solving tools, professional and office aids, 
and books, periodicals and accessories. 

Catalog Department. Lifeboat Associ- 
ates. 1651 Third Ave.. New York. NY 
10018.(212)860-0300. 

BASIC AND FORTRAN 
COURSES 

Heathkit/Zenith Educational Systems 
announces two computer programming 
courses, the EC- 1101 Fortran Programming 
Course and the EC- 1 1 10 Microsoft Basic 
programming course. 

The Fortran course teaches the funda- 
mentals of programming in Fortran, with 
a 500-page text and six cassette tapes. 
$99.95. 

The Microsoft Basic course features a 
500-page text and three audio cassettes 
which teach the user how to get the most 
out of MBasic. $99.95. 

Heathkit/Zenith Educational Systems. 
Dept. 350-055. Benton Harbor. MI 49022. 

CIRCLE 364 ON READER SERVICE CARO 

CREATIVE COM PUT ING 



$670.00 



$3500.00 



MODEL I 

1 6K Level! I with Keypad 
26-1056 



MODEL II 

MODEL II, 64K 
26 - 4002 



SmWoII 



$825.00 

MODEL III 

MODEL III 16K RAM, 

MODEL III BASIC 

26-1062 




HHH 

CrsU'lcTBON-CS. LTD. 3, ^. a&"l&" ^ Sgll^ 



FULL FACTORY WARRANTY 
ON ALL ITEMS SOLO. 



NEW! ASCII 

■ ^ "™ for the TRS-80* 
Every month you receive . certified ASCII C-20 ca.sett. 
clTn.no: . cov.r page with . directory of program. 
4 original program* 
an Information packed newslattar 
and Information on ASCII funded contaata 
Rates: 1 year [12 lesuesl *40.00 
6 montha (6 Issues] $25.00 
Sample Issue * 5.00 

Writ* For Overseas Rata* 
To subscribe, write to. ASCII 
P O Box 516, Valley Stream, NY. 11582 
' Or call: 516-791-4890 



TER STORE »R491 



ELECTRONICS MAR 





C.RCLE119GN READER SERVICE CARD 



CIRCLE 1160N READER SERVICE CARD 



hrrmM'V™" ra"ER DISCOUNTS « 



j|cippkz K 
i6K computer 

Disk II wit" Controller S535. without S446 



SOFTWARE 

Advanluia by *«"* " „ 

AM" Ram by »'o*a>tHi"d 

Applabug Oabuggar 

Appla Graph » P»l u-rf-i 

Applaaoll U y R'»« CM. »» »••••«> 

Ap(jla*»"l»r 

»,i..o.<i f ■•w »v c, "?„*:_ 

Budgai Spaca Gam. Album 
b„dur* 3D Graphic* ita ... 

CC A O... Mgml by Pa'"— Sotl—a 
Cybar »»»• »» s, " u * ,„„ 
OAKIN S Programming Aid 3 J 
Dal* Factory By M.crolab 
DB Ma*l*r II *>y Slonawara 
O..Mop Plan II by P..**.* Solt«ara 
DOS Tool ml m ■ tM 

DO. Jona* PorlloKO E.alualor 
Fngni Simulator by Sub-Logic 
Form II by Sonapa 
Fortran „ , _ ' 

M, Re. Foolball by On Lino 
PASCAL Lan«UA«a SyMam 
p.i.on.L filing Sy*lam 
M..1.1 Blaalar by Ruopaoo 



24 



Saigon II Cha»* by Kayoa* a 

Soaca Egg* by Strlu* M 

*!£** M by P*nonil Sottwef* 1 *J 

ZORK by Personal Software 

ACCESSORIES FOR 
THE APPLE II 

ART Numarlc KoypoO «"« «« • 111 

»IS Snwl.rm 40 cokmm board 5" 

And.om.da t« R.mcard J^ 

Appla Cloc. C.laada. by Mm Camp. «| 

ApplaKill B...C F«m...* Card "! 

3l»~llc F.OOM ■'•" by CC» »M 
LK9 . f^Wcllo" Ol Solmm.0 Ju.l CALL 

WE SHIP FAST! 



A.»ncKronou* Sorul .7710A by CCS 

JpS Mum Funcl.on C.d by Mm Comp 

C.nl.onic. Card by »»•• 

Communication A DB25 CpBM 

DOS 3 3 Upgrad. Kl' 

Graphic* Input l«*l by Appal 

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CIRCLE 232 ON READERSERvlcECARD 1 



ATTENTION: ATARI* USERS ■ 
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CIRCLE 120 ON READER SERVICE CARD 



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COMPUTER CENTER, 

W»ei<days 10-8: s»t 105 ^^ 



174 



CIRCLE 177 ON READER SERVICE CARO 

CREATIVE COMPUTING 



New Products, continued... 

SYSTEMS 
SOFTWARE 

LANGUAGES 

Texas Instruments has announced 77 
Logo, a computer language designed to 
help students in primary grades through 
high school develop problem-solving skills. 
In addition to the software, the complete 
Logo system requires a standard Tl 99/4 
equipped with monitor, disk drive, disk 
controller and memory expansion unit. 
$299.95. Texas Instruments, P.O. Box 53, 
Lubbock. TX 79408. 

CIRCLE 365 ON READER SERVICE CARD 

Vigil is an interactive graphics and game 
language for PET/CBM computers. Fea- 
tures include: more than 60 commands to 
manipulate graphics features on the screen, 
double density graphics which provides 
80 x 50 positions on 40-column machines, 
and access to two event timers. $35. Abacus 
Software. P.O. Box 7211, Grand Rapids. 
MI 49510. 

CIRCLE 366 ON REAOER SERVICE CARD 

SYSTEMS 

Comal is a structured language said to 
be similar to Pascal, but easier to learn. 
An information packet available free of 
charge to PET/CBM users contains infor- 
mation on user groups, books, articles 
and software. It also provides instructions 
on obtaining a free Comal compiler. The 
Comal Users' Group, 5501 Groveland Ter.. 
Madison. VT 53716. 

Computerware introduces a Color Edkor 
on cassette for the Radio Shack Color 
Computer. It allows use of upper and 
lower case as well as change and search 
commands. $24.95. Also available is Color 
Assembler, a 6809 machine code assembler 
which supports all 6809 mnemonics and 
addressing modes along with standard 
assembler options and directives for the 
Color Computer. $29.95. Both programs 
require the power pack. Computerware. 
Box 668. 1512 Encinitas Blvd.. Encinitas. 
CA 92024. (714) 436-3512. 

CIRCLE 367 ON READER SERVICE CARD 

The Software Toolworks announces a 
group of programming languages and other 
software tools for use on CP/M systems. 
They include: the C/80 C Compiler which 
implements a subset of the C programming 
language: Lisp/90, an 8080 implementation 
of an artificial intelligence language: the 
RATFOR preprocessor which provides 
structured programming constructs for 
Microsoft Fortran: a text formatter; and 
Z-80 and 8080 opcode versions of the 
UVMAC macro assembler. Prices range 



from $20 to $40. The Software Toolworks. 
14478 Glorietta Dr.. Sherman Oaks. CA 
91423. (213) 986-4558. 

CIRCLE 366 ON READER SERVICE CARO 

Mince is a video text editor for use on 
CP/M systems. It is written in C and offers 
upward compatibility from 8080 and Z-80 
microcomputers to 16-bit computers. $125. 
Westico. Inc.. 25 Van Zant St.. Norwalk. 
CT 06855. (203) 853-6880. 

CIRCLE 369 ON READER SERVICE CARD 

DATA BASE MANAGEMENT 
SYSTEMS 

C.O.R.P. database management system 
is a program generator that allows the 
user to write data-base management sys- 
tems in Applesoft Basic. The system 



requires an Apple II Plus or Apple II with 
at least 48K of memory, two disk drives 
(DOS 3.3). auto-start ROM and Applesoft 
in ROM. $189.95. Maromaty and Scot to 
Software Corp.. P.O. Box 610. Floral Park. 
NY 11001. 

CIRCLE 370 ON READER SERVICE CARD 

The Express option for the Oasis oper- 
ating system combines the capabilities of 
an English-like inquiry language and an 
advanced program generator in a multi- 
user relational database management 
system. The program uses "free-form" 
sentences to compare, manipulate and 
report information from multiple files. $695. 
Phase One Systems. 7700 Edgewater Dr.. 
Suite 830. Oakland. CA 94621. (415) 562- 
B0&5 

CIRCLE 371 ON READER SERVICE CARD 



raeara 



Do you like thinking games? 
Do you like fast-action 

spectator sports? 
Want to have fun learning 

more about computers 

and programming? 
Think you can program 

better than your friends? 

If you answered YES to any of fhese questions. 
RobotWbr is ten you A game of the future you 
can play today 

Create a robot by writing a special Battle 
Language program This program gives your 
robot its unique fighting personality 
Debug your robot on the lest Bench, 
a cybernetic window into your Robot s 
mind Is it really checking its 
damage level to consider evasive 
action? Does it increment its radar 
and lasar cannon aim while search 
ing for enemies' 5 If all checks out. 
it's on to 

The Battlefield Challenge up to four competitors from the Robot Reody Room on your disk 
Your robot will meet them in the arena where you have a bird's eye view of the mechanical 
carnage Robots scurry about, radars flash, lasar shots fly and explode and only one sur- 
vives You're the witness to a futuristic Gladiator spectacle 

Available on disk for the Apple computer with 48K and Applesoft ROM. at computer stores 
everywhere 

from the leader in quality software 




Cj» o> «■»'«• to* mtarmoKjn ana 

fn» mm* of vom rwoHWi MUi Omatm 



MUSE 



SOU WAR! ' 



AUGUST 1981 



CIRCLE 225 ON READER SERVICE CARD 



175 



330 N CHARLES STREET 
BALTIMORE. MD 21201 
.(301)659-7212 



Why would anyone spend $59.95 for a joystick? 



Super 
Joystick 



Star Wars. Played with paddles, its difficult 
at best and frustrating at worst. But with 
a joystick it becomes an entirely new 
experience. Its still challenging. Its also 
fun. And very addictive. 

Have you ever used a drawing program 
in which one paddle controls the horizontal 
movement of the "brush" and the other 
paddle the vertical? Its slow, tedious work 
But with a joystick, drawing is an absolute 
joy. 

Exceptional Precision 

The Apple high-resolution screen is divided 
into a matrix of 160 by 280 pixels. To do 
precise work on this screen, you need a 
precise device Most potentiometers used 
in paddle controls are not quite linear. If 
you rotate a paddle control at a constant 
speed, you II notice that the cursor speeds 
up slightly at the beginning and end of the 
paddle rotation. 

The Super Joystick has a pure resistive 
circuit which is absolutely linear within one 
tenth of one percent. In other words it would 
give you precise control over an image of 
1000 by 1000 pixels, were such resolution 
available Thus it is suitable for high precision 
professional applications as well as educa- 
tional and hobbyist ones. 

Matched to your application 

The Super Joystick also has two external 
trim adjustments, one for each direction. 
This allows you to perfectly match the unit 
to your application and computer. Say you 
want to work in a square area instead of the 
rectangular screen. Just reduce the horizontal 
size with the trim control. 

How many times have you played Space 
Invader and had your thumb ache for hours 
from the repeated button pressing? This 
wont happen with the Super Joystick. It's 
two pushbuttons are big. Moreover, they 
use massive contact surfaces with a life of 
well over 1 ,000,000 contacts. A few games 
of Super Invader using these big buttons 
will justify the purchase of the Super Joy- 
stick. 

The Super Joystick is self-centering in 
both directions. That means when you take 
your hand off it, the control will return to the 
center. However, if you want it to stay where 
you leave it, self-centering may be easily 
disabled. 

The Super Joystick plugs right into the 
paddle control socket and doesn't require 
an I/O slot. 



High-quality construction 

The sturdy metal case of the Super Joystick 
matches that of the Apple computer. Every 
component used is the very highest quality 
available. The Super Joystick even uses a 
full 16-conductor ribbon cable so you can 
add a second joystick if you wish. The first 
Super Joystick replaces Paddles and 1 . 
You may not realize it, but the Apple can 
support four paddle controls A second Super 
Joystick would replace Paddles 2 and 3. 




By removing two springs, self-centering 
can be defeated. 

We invite your comparison of the Super 
Joystick with any other unit available Order 
it and use it for 30 days. If you re not 
completely satisfied, return it for a prompt 
and courteous refund plus your return 
postage You can t lose. 

The Super Joystick consists of a self- 
centering, linear joystick, two trim controls, 
and two pushbuttons mounted in an attractive 
case. It comes complete with an instruction 
booklet and 90-day limited warranty Cost 
is $59.95. 

Order Today 

To order the Super Joystick send $59.95 
plus $2.00 postage and handling (NJ 
residents add $3 00 sales taxjto our address 
below. 

Experience the joys of using the world's 
finest joystick Order your Super Joystick 
at no obligation today. 

39 East Hanover Ave 
Morris Plains. NJ 07950 
Toll-free 800-631 -8112 

(In NJ 201-540-0445) 



New Products, continued... 

InfoHO is a filing and information man- 
agement system designed to run on the 
TRS-80 Models I and III with 48K and 
disk drives. The system supports continu- 
ously variable record input length and 
automatically creates and extends disk 
files. $100 on data diskette; $115 on 
TRSDOS diskette. Bluebird's Computer 
Software. 2267 23rd St.. Wyandotte. MI 
48192. (313) 285-4455. 

CIRCLE 372 ON READER SERVICE CARD 



APPLICATIONS 
SOFTWARE 



GAMES AND RECREATIONAL 

Manhattan Software announces four 
programs for the Atari Personal Computer: 
Gin Rummy, which requires 32K of mem- 
ory and one joystick ($19.95); Casino 
Blackjack /Counter for 24K and one joy- 
stick (S19.95); Labyrinth Run in which 
the player uses the joystick to guide a 
fast-moving runner through twisting course 
($14.95); and Concentration, a two-player 
version of the match-the-card game, which 
requires 16K or 24K and two joysticks 
($14.95). Manhattan Software. P.O. Box 
35. Pacific Palisades. CA 90272. (213) 454- 
8290. 

CIRCLE 373 ON READER SERVICE CARD 

Automated Simulations has released 
three EPYX games for the 32K Atari 800. 
In Invasion Orion, a tactical space battle 
game, the player controls up to nine space 
ships armed with destructor beams, tractor 
beams, missiles and torpedos. against the 
computer ($24.95). In the Datestones of 
Ryn. the player must recover the stolen 
Datestones of the ducal calendar from 
within a maze ($19.95). Rescue at Rigel is 
a science fiction, role-playing game in 
which the player has 60 minutes to find 
10 humans held captive inside an alien 
moonbase ($29.95). Automated Simula- 
tions. Inc.. P.O. Box 4247. Mountain View. 
CA 94040. 

CIRCLE 374 ON READER SERVICE CARD 

Cribbage for the TRS-80 Models I and 
III is written in Basic with machine 
language patches. It will work on Level I. 
II or DOS systems. $16.95 on cassette; 
$19.95 on disk. The Alternate Source. 
1806 Ada St.. Lansing. MI 48910. (517) 
487-3358. 

CIRCLE 375 ON READER SERVICE CARD 

Space Raiders is an animated, machine 
language, graphics program designed to 
rival popular arcade style games. There 
are five levels of simulation and every 
game is different. The program runs on 
the 16K Level II TRS-80 Model I. $24.95. 



CIRCLE 239 ON READER SERVICE CARD 



176 



CREATIVE COMPUTING 




Bosen Electronics. 445 East 800 North. 
Spanish Fork. Utah 84660. (801) 
798-9553. 

CIRCLE 376 ON READER SERVICE CARD 

EDUCATION 

Classfile is a classroom record-keeping 
program for the 16K TRS-80 Models I 
and III. The program allows the teacher 
to produce: a list of all students in a class 
and their grades, a list of all students 
whose grade falls below a cut-off point, a 
list of all students and averages in rank 
order by average, the class average or the 
average of any student by name. $19.95. 
TYC Software. 40 Stuyvesant Manor. 
Geneseo. NY 14454. (716) 243-3005. 

CIRCLE 377 ON READER SERVICE CARD 

Edu-Ware Services announces a new 
product line. Interactive Fantasies, which 
includes The Prisoner, Terrorist. Windfall. 
Network. Space and Space II. Also avail- 
able is Perception Version 3.0 which 
includes seven programs to challenge the 
user's visual judgment and sharpen his 
eye-hand coordination. Edu-Ware Services. 
Inc.. 22222 Sherman Way. Ste. 102. Canoga 
Park. CA 91303. (213) 346-6783. 

CIRCLE 378 ON READER SERVICE CARD 

BUSINESS 

Long Distance Analyzer is a business 
program for the TRS-80. The program 
matches a phone bill with a file of recog- 
nized numbers; calls are grouped and 
totalled by number to help in cost account- 
ing, billing clients, and investigating unfa- 
miliar numbers. Usage patterns are ana- 
lyzed by area code, state and WATS zone. 
Cassette version for Models I and II. S95; 
disk version. $135; Model II disk. $155. 
Golden Braid Software. P.O. Box 2934. 
Sarasota. FL 33578. 

CIRCLE 379 ON READER SERVICE CARD 

Cybersoft announces Version 5.0 of 
Medical Billing System. Written in CBasic- 
2 for CI' M -based systems, the package 
consists of 21 menu-driven programs for 
operating a medical practice. Cybersoft. 
433 Valley Ave.. Birmingham. AL 35209. 
(205) 942-8567. 

CIRCLE 380 ON READER SERVICE CARD 
Charles Mann & Associates has intro- 
duced Payroll I for the TI 99/4. The system 
allows a small business with fewer than 
100 employees to operate a weekly, bi- 

AUGUST 1981 



HlRRk GORIDOn 



-^tt; 



DIVISION OF MARK GORDON ASSOCIATES. INC. 
P.O. Box 77, Charlestown, MA 021 29 (61 7) 491-7505 



COMPUTERS 

Alan 800 W16K 799 00 

4K Model Mi 599 00 

Model II 64K System 3499 00 

16K Model III 879 00 

DISK DRIVES 
40 Track 5% inch drive 



80 TracH 5' « 
4 Disk Drive Cable 
Lobo w/coniroHer 
L obo w/o controller 



314 00 

544 00 

39 00 

Call lor price 

Call tor price 



PRINTERS 
Epson MX80 
Epson MX70 
Okidala Microlme 80 
Okidata Microlme 82 
Okidata Microline 83 
NEC5510w-tractor 
Diablo 630 



Call for price 

Call for price 

479 00 

699 00 

989 00 

2679 00 

2495 00 



MISC HARDWARE 

Expansion ml TRSMXC*) 269 00 

Novation D-Cat Modem 166 00 
16K Memory Kit 35 0012/65 00) 

Leede« Monitor 1 49 00 

Leede« 100G 16900 

Leedei Color Monitor 399 00 

Printer Cable for above . 49 00 

ISO- 2 Isolator 54 00 

AC LINE FILTER 24 00 

280 Soltcard 289 00 

Ramcard 1 69 00 

Vide. 80 COL BOARD 289 00 

Vide« KBO Enhancer 1 09 00 

DC Hayes Micro Modem II 31900 
CCS and SSM Interface 

Cards Call for price 

STORAOE MEDIA 

Scotch-box 10-5'4 27 00 

Memoreibon 10-5'< .22 00 

Plastic Storage Bot 5 00 

^Verbatim 5' i 25 00 



OPERATING SYSTEMS 
NEWDOS by APPARAT INC 
NEWDOS-r by APPARAT INC 
MMS FORTH DISKETTE PRIMER 
NEWDOS 80 
VTOS 



49 00 
99 00 
79 95 
135 00 
99 00 



BUSINESS SOFTWARE FOR TRS-80. APPLE AND ATARI 
Free enhancements and upgrades to registered owners tor the cost of media 
and mailing 30 day free telephone support User reference on request 
Fully Interactive Accounting Package General Ledger. Accounts Payable. 
Accounts Receivable and Payroll Report Generating 

Complete Package (requires 3 or 4 dnves) 475 00 

Individual Modules (requires 2 or 3 drives! 1 25 00 

Inventory II (requires 2 or 3 drives) 99 00 

Mailing List Name A Address II (requires 2 drives) 1 29 00 

Intelligent Terminal System ST-80 III 1 50 00 



The Electric Pencil from Michael Shrayer 

File Management System 

Son 80 

L JK Letter Perfect (Atari Apple) 

DB Master (Apple) 

Disk Business Software available tor Model III 



150 00 
49 00 
5900 
139 00 
169 00 
Call lor price 



FINE PRINT 
TRS-80 is a Tandy Corporation trademark Use of above operating systems 
may require the use of Radio Shack TRS-DOS Radio Shack equipment 
subtect to the will and whim of Radio Shack 

ORDERING INFORMATION 
We accept Visa and Mastercharge We will ship COD. certified check, or 
money order only There will be a 40 percent deposit required on all C O 
orders over $300 00 Massachusetts residents add 5 percent sales tai Stock 
to three weeks tor delivery 

TWX #710-320-7693 

For information call 617-491-7505 

To order, call toll-free 1 -800-343-52O6 

The Company cannot be liable for pictorial or typographic inaccuracies 
The above pnces do not include shipping. 



CIRCLE 16S ON READER SERVICE CARD 



INNOWITVE 




We figure tin- more innovative we are 
th«- more you'll benefit. iv« work hard 
at providing you with more In-depth 
software and hardware analyses, inter- 
views, industry news and trends. 

Its all then-, every other week, in In- 
foWorld. If you have a special interest in 
personal computing, you can't afford to 
miss another Issue of thj? microcom- 
puter newspaper: infoWorld. 

Mail this form or facsimile to: 
[nfoWorid, 375 Cochituate Road. 
Framingham, Mass. 01701 

()i t all (8001 343-6474 

IiifoWorld 



j Please start my miIim ription iii InfoWorld, the TikTWJnuwnw rniinpa|M 

■ D $18 one year (26 issues) Over 44% savings off newsstand price 



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,_i My check is wiflnsnTl i ] Bill Me 

I Charge my I ! MSSlrHlllSiew I RankAmerirard VMU 

I IMC onh list 1 dibits ahove your name ) 

I Card No Exp Date 



□ American Express 



| Signature 

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j InfoWorld, 375 OorNll al h J Road. Framingham, Mass. 01701 18(H)) 343-6474 



Htatc 



Zip I :€Mte 



177 



CIRCLE 208 ON READER SERVICE CARD 



New Products, continued... 

weekly, semi-monthly or monthly payroll. 
It requires a single disk drive, small printer. 
Extended Basic and 16K. The program is 
also available for 32K Apples. $199.95. 
The Construction Accounting System, for 
Apple II Plus and Apple III. is a general 
ledger, payroll, job cost accounting and 
sub-contractor records system. $399.95. 
Charles Mann & Associates. 55722 Santa 
Fe Trail. Yucca Valley. CA 92284. (714) 
365-9718. 

CIRCLE 381 ON READER SERVICE CARD 

Address Management System runs under 
CP/M and can print labels up to five 
across sorted on up to three fields. It 
works in conjunction with Magic Wand 



to produce customized letters. $150. Ivanco. 
5131 Silver Arrow. Rancho Palos Verdes. 
CA 90274. 

CIRCLE 382 ON READER SERVICE CARD 

Advanced Data Systems has announced 
the expansion of its product line to include 
software for the 48K Apple. The following 
programs are available: Business Plus, a 
complete business system aimed at the 
small business owner ($299.95): Maflnuster. 
mailing list program that works with most 
popular printers ($69.95): Intelligent Lister. 
a program to format Applesoft and Integer 
Basic program listings ($34.99); Master 
Copier, a bulk diskette copier ($29.95): 
Codex Catalog, a disk catalog program 
($34.95); and Modem Utilities, a collection 



SUPER-TEXT 



ADVAN 
FEATURES 

C split screen tor editing large 
documents 

Math Mode tor preparing 
statistical reports 

Optional (>>e linking lor global 
search and print operations 

Preview Mode formats line 
endings and page breaks on 
screen before printing 
[ Form letter generation and 
mailing list management 
addon modules 
and much more 




OF USE 

. single key cursor control 
automatic word overflow 
automatic paragraph 

indentation 

automatic on-screen tabbing 
block copy, save and delete 
tutorial manual and handy 

reference card 

I dual disk copy program tor 

tile backup 
and much more 




Super-Text is the word 
processing answer A rare ^ 



combination of ease of use and 
advanced features Super-Text turns an 
Apple computer into a powerful word 
processing system with capabilities 
unmatched by many dedicated WP sys- 
tems costing thousands of dollars more 



Add the Form Letter 
Module and Address Book to 
, make Super-Text the most 



powerful business correspondence 

system Use Super-Text to create a letter. 

then print a personalized copy for everyone 

on your mailing list Super-Text is $150. the 

Form Letter Module $100 and the Address 

Book $50 at computer stores everywhere 



From the leader in quality software... 



For the Apple II or Apple II Plus(48K| 
AooM i» a tiadftmarh or Aoc*e Computer Corp 



MUSE 



SOFTWARE - 



330 N Charles St 
Baltimore. MD 21201 
■ (301)659-7212 



CIRCLE 226 ON READER SERVICE CARD 



of utilities for owners of the D.C. Hayes 
Micromodem II. $59.95. Advanced Data 
Systems. 7468 Maple Ave.. St. Louis. MO 
63143.(314)781-9388. 

CIRCLE 3S3 0N READER SERVICE CARD 

UEMS is a commercially oriented bul- 
letin board system designed for the trans- 
mission of information through a central 
host TRS-80 Model I with 48K of memory 
and two disk drives. The program allows 
for billing users for their time on the system 
and/or monitored access to particular 
pieces of mail. $150. Small Business Systems 
Group. Inc.. 6 Carlisle Rd.. Westford. 
MA 01886. 

CIRCLE 384 ON READER SERVICE CARD 

A client write-up system for CP/M 
systems is designed for the certified public 
accountant. The general ledger system 
includes a video journal entry program 
with automatic paging, on-line account 
verification, automatic journal balancing 
and control over nine separate journal 
books. Micronetics. Inc.. 1926 Hollywood 
Blvd.. Suite 328. Hollywood. FL 33020. 
(305) 925-2333. 

CIRCLE MS ON READER SERVICE CARD 

Micro Associates announces three pro- 
grams for the TRS-80 Model II. Payroll 
with Invoicing is a management tool for 
consulting firms, construction companies 
and contractors. MatStal is a program to 
generate and maintain material status 
reports for engineering and construction 
projects. And ProSched is a management 
program for estimating manpower require- 
ments over the anticipated life of a project. 
All three programs are also available to 
run under CP/M in Microsoft Basic. Micro 
Associates. P.O. Box 6316. Metairie. LA 
70009. (504) 831-3562. 

CIRCLE 386 ON READER SERVICE CARD 

Four software packages for business 
have been introduced by Personal Soft- 
ware Inc.: VisiPlot. a high-resolution 
plotting and graphics package ($179.95); 
VisiDex. a flexible personal information 
system ($199.95): VfalTrend/VbiPlot. a 
combination of VisiPlot graphics and a 
program for time-series manipulation, trend 
forecasting and descriptive statistics 
($259.95); and VlslTerm. which allows a 
personal computer to communicate with 
a variety of other computers, ranging from 
mainframes to micros ($149.95). The 
programs are available for the disk -based 
Apple II and Apple II Plus with 48K of 
memory. Personal Software. Inc.. 1330 
Bordeaux Dr.. Sunnyvale. CA 94086. 

CIRCLE 387 ON READER SERVICE CARD 

Micro-Courier allows owners of Apple 
computers to transmit charts, graphs, 
correspondence. VisiCalc reports and 
entire programs to other Apple computers 
over the phone lines. $250. Also available 



178 



CREATIVE COMPUTING 



DISCOUNT PRICES 




RAM MEMORY 

FOR TRS-80. APPLE II 
16KSET4116s(200NS) 



34 95 




16K APPLE II 


1089 00 


400 16K 


34900 


32K APPLE II 


1134.00 


800 16K 


759.00 


48K APPLE II 


1179.00 


410 Recorder 


64.00 


DISK W/CONTROLLEP. 


535.00 


815 Disk 


1199.00 


DISK ONLY 


455.00 


810 Disk 


489.00 


APPLESOFT CARD 


159.00 


822 Printer 


359.00 


INTEGER CARD 


159.00 


825 Printer 


779.00 


PASCAL SYSTEM 


425.00 


830 Modem 


159.00 


SILENTYPE PRINTER 


525.00 


850 Interface Module 


179.00 


HAYES MICROMODEM 


295.00 


CX853 RAM 


85.00 


Z-80 SOFTCARD 


295.00 


CX70 Light Pen 


64.00 


VIDEX80COL. BRD. 


295.00 


CX30 Paddle 


18.00 


16K RAM BOARD 


169.00 


CX40 Joystick 


18.00 



VERBATIM DISKETTES 

Box of 10 S'V 29.50 

Box of 10 8" 3950 




North Star Computers 

HR2-2D-32K 2795.00 

HR2-20-48K 2956.00 

HR2-2D-64K 3145.00 

HR2-2Q-32K 2975.00 

HR2-2Q-48K 3165.00 

HR2-2Q-64K 3360.00 

HRAM 32K 469.00 

HRAM 48K 662.00 

HRAM64K 849.00 

HDS-18 HARD DISK 4025.00 

MDS-DRV-D 495.00 

MDS-DRV-Q 665.00 

ADC- ID 740.00 

ADC-2D 995.00 

ADC-1-Q 795.00 

ADC-2Q 1285.00 



PRINTERS 

EPSON MX-70 399.00 

EPSON MX-80 499.00 

EPSON MX-80 FT 599.00 

GRAFTRAX 90.00 

INTERFACE (APPLE) 75.00 

CABLE 2250 

CENTRONICS 737-1 795.00 

CENTRONICS 737-3 855.00 

IDS445G 815.00 

IDS460G 1195.00 

IDS560G 1450.00 

NEC 5510 W/TRACTORS 2650.00 
NEC 5520 KSR W/TRAC. 2995.00 

QUME 5/45 SPRINT 2675.00 

FORMS TRACTOR 195.00 

STARWRITER W/TRAC. 1695.00 
STARWRITER W/O 

TRACTOR 1500.00 



General Information: 

We carry a large selection of hard- 
ware and software by other com- 
panies. Send for our catalog. 
We are an authorized repair center for 
APPLE. ATARI. NORTH STAR. AND 
EPSON 



PRICES SUBJECT TO CHANGE WITHOUT NOTICE. MARYLAND RESIDENTS ADD 5% SALES TAX 



FREDERICK 57 26 industry lane 

COMPUTER FREDERICK, MD. 21701 

PRODUCTS, INC. TO ORDER CALL: (301) 694 8884 

CIRCLE 178 ON READER SERVICE CARD 



Store Hours: 

MON. THRU THURS. 9:30 AM— 9:00 PM 
FRI. AND SAT. 9:30 AM— 5:00 PM 



The first and only 
HIRES color graphics pool 
simulation tor the Apple II 
or Apple ll Plus. 

• Meal lime color HIRES 
animation 

• 2~>(i directions tor aiming 

• 4 popular games 

Eight Ball 
Straight Pool 
Rotation 
Nine Ball 

• Instant replay lor any shot 

• S|K'c ial "slow-motion" 
control 

• Bool l.s supports the best 
i llR.ES animation on the 
Apple today. YouVe got to 
see ii to believe it! 

• Dealer inquiries invited. 

\n*' * \|»|tk-ll.iH- rirtiHHrtUH.whm.irtu.oi Applri mtp|0tf» H* 

•I \ ■ >i i -. I- .t h.« V-i iktrfc < m i 1 1 s l 



Pool 1.5* for the Apple II 



13 



<TS5 



zmi 



Bv 



INNOVATIVE DESIGX SOFTWARE. INC. 



P^lllllllllllllllllllllllllllllllllllllll 

! | <«> © l0>O 

■ • 


8 

^■PP 


■ mi 

**. Wl 
<*> 





only $34.95 ppd. 

Requires: 48K Apple 11 
with Disc II and Paddles 



Stf \<>ur lot .ii ik .tic r < >r order dim m ir-itu ll >si 
New Mexico ns.dciilx .iiiil 425% lav 
Visa & Matter ( «trd «ic i epied 



IDSI 

p.o. a<>.\ ih.->m 

Las ( ruces. S.M. hh<x)4 

(-»()->) 52 2 7373 



CIRCLE 147 ON READER SERVICE CARD 



AUGUST 1981 



179 



New Products, continued. 



0" 



is Micro-Telegram which allows Apple 
owners to access Western Union Service 
to send mailgrams and send and receive 
TWX. Telex and international cables. $250. 
Microcom. 89 State St.. Boston. MA 02109. 
(617) 367-6362. 

CIRCLE 388 ON READER SERVICE CARD 

WORD PROCESSING 

The Computerized Dictionary, designed 
for the SouthWest 6809 computer, edits 
word processing text for spelling errors 
and changes them automatically. Davidson 
Software Systems. Box 21001. Lansing. 
MI 48909. (517)332-5989. 

CIRCLE 389 ON READER SERVICE CARD 





THREE 

MILE 

ISLAND 

bv Rcnard Cuban 




Put yourself in control of a nuclear reactor! 



The olds you hove in oper oting the ptont 
ore excellent meyinciiKfefcHjrgrophical 
views of portions of the plant, on Instrument 
pan*, a financial summon/ and on equip- 
ment status and failure log '" 

"As o simulation Three Mile Island Is excel 
lent As a gome It Is fascinating to me " 

Victor Fncke Nuclear engineer in the March 
1980 issue of Creative Computing 



"This program will be a classic." 

"No school should be without Three MHe 
Island If parents ore buying o computer for 
the personal development ond education at 
their children they must buy this program " 

Robert EHrot Purser pubirsher of Purser s 
Magazine A Software Directory 



$3995 
For the Apple II and Apple ■ Plus (48K) 



CaffWtrfvG 



MUSE 



SOFTWARE" 



330 N CHARLES STREET 
BALTIMORE. MD 21201 
(301)659-7212 



Cat o» M«fe tof o HJK cak*ogot 
m» nam* at vouf nsamr MUSE a 



CIRCLE 227 ON READER SERVICE CARD 



Proofreader works with any word pro- 
cessor to check for spelling errors using a 
38.000-word dictionary. It is available for 
32K TRS-80 Model I with disk ($54). 64K 
Model II with disk (S109). and 32K Model 
III with disk ($64). Soft-Tools. MHE Box 
14. Tijeras, NM 87059. 

CIRCLE 390 ON READER SERVICE CARD 



PERSONAL 

The Money Maestro home banking 
system, written in Forth, is designed to 
provide financial record-keeping, tax 
reporting and budgeting for professionals. 
clubs, families and very small businesses. 




The system is available for CP/M systems 
with at least 48K of memory and 140K of 
disk storage. InnoSys Incorporated. 2150 
Shattuck Ave.. Suite 901. Berkeley. CA 

94703.(415)843-8122. 

CIRCLE 391 ON READER SERVICE CARD 

Video Librarian is designed to maintain 
an accurate file of home video cassette 
programs and tapes. It can handle plot 
summaries, movie ratings, editing codes, 
running lengths, audience rating codes, 
hard copy print-outs, and personal nota- 
tions. Available in Applesoft for the 48K 
Apple with DOS 3.2 or 3.3 $19.95. Sof- 
tronix. Suite 1000. 4600 Park Rd.. Charlotte. 
NC 2821 1.(708) 334-1958. 

CIRCLE 392 ON READER SERVICE CARD 

MISCELLANEOUS 

All entries in a rapid-retrieval database 
covering Apple literature through 1980 
include article title, author name, periodical 
name, date of issue and page number. 
The product requires Applesoft in ROM 
and 48K of RAM. Annual updates will be 
available. $60. Connecticut Information 
Systems. 218 Huntington Rd.. Bridgeport. 
CT 06608. (203) 579-0472. 

CIRCLE 393 ON READER SERVICE CARD 



180 



CREATIVE COMPUTING 



iu RACET SORTS — RACET UTILITIES — RACET computes - RACET SORTS - RACET UTILITIES - RACET computes — RACET SORTS — RACET UTILITIES - RACE! computes - 



HARD DISK MULTIPLEXOR WITH 10 MEG HARD DISK 

FOR THE TRS-80* Mod II 
NOW YOU CAN HAVE THAT URGE COMMON DATA BASE!! 

• Allows up to 4 Mod II s to connect to a single controller — up to 4 hard disk 
drives per controller. Users may access the same tile simultaneously (first-come 
tirst-served). 

• Uses Cameo controller and standard 10-megabyle cartridge (hard) disk drives 
along with RACET Hard/Soft Disk System (HSD) software 

• Access times 3 to 8 times faster than floppy Mixed floppy/hard disk operation 
supported. 

• Compatible with your existing TRSDOS programs! All BASIC statements 
are identical 

• A single tile may be as large as one disk Alternate mode allows 24 million 
byte record range. Directory expandable to handle thousands ot files 

• includes special utilities — backup and copies. HPURGE for multiple deletions. 
HDCS directory catalog system, and Hard Disk Superzap FORMAT utility 
includes options tor specifying sectors/gran, platters/drive, logical disk 
size, etc 

HARD DISK DRIVE « CONTROLLER $5995 RACET HSD Software $400 

Call for multiuser pricing Dealers call for OEM pricing 

INFINITE BASIC (Mod I & III Tape or Disk) Mod I $50.00. Mod III $60.00 

Extends Level II BASIC with complete MATRIX functions and SO more string 
functions Includes RACET machine language sorts' Sort 1000 elements in 9 
seconds' ' Select only functions you want to optimize memory usage 

INFINITE BUSINESS (Requires Infinite BASIC) Mod 1 1 III $30.00 

Complete printer pagination controls — auto headers, footers, page numbers 
Packed decimal arithmetic — 127 digit accuracy +, -, *, /. Binary search 
of sorted and unsorted arrays Hash codes 

BASIC CROSS REFERENCE UTILITY (Mod II 64K) $50.00 

SEEK and FIND functions for Variables. Line Numbers. Strings. Keywords All' 
options available for line numbers and variables. Load from BASIC — Call with 
CTRL'R Output to screen or printer' 

DSM Mod I $75 00. Mod II $150.00. Mod III $90.00 

Disk Sort/Merge for RANDOM files All machine language stand-alone package for 
sorting speed Establish sort specification in simple BASIC command File. Execute 
from DOS. Only operator action to sort is to change diskettes when requested! 
Handles multiple diskette tiles' Super last sort times — improved disk I/O times 
make this the fastest Disk Sort/Merge available on your TRS 

(Mod I Min 32K 2-dnve system Mod II 64K 1 -drive. Mod III 32K 1 -drive) 



+ *NEW** DISCAT(32K1 -drive Mm) Mod I. Ill $50.00 

This comprehensive Diskette Cataloguing/Indexing utility allows the user to keep 
track of thousands of programs in a categorized library Machine language program 
works with all TRSDOS and NEWOOS versions Files include program names and 
extensions, program length, diskette numbers, front and back, and diskette tree space. 

* * NEW* * 

KFS-80 (1 -drive 32K Min — Mod H 64K) Med I, III $100.00; Mod II $175 00 

The keyed tile system provides keyed and sequential access to multiple tiles Provides 
the programmer with a powerful disk handling facility lor development of data base 
applications. Binary tree index system provides rapid access to tile records 

* * NEW * * 

MAILLIST ( f -drive 32K Mm - Mod II 64K) Mod I. Ill $75.00; Mod II $150.00 

This ISAM-based maillist minimizes disk access times Four keys — no separate 
sorting Supports 9-digit zip code and 3-digit state code Up to 30 attributes. Mask 
and query selection Record access times under 4 seconds!! 

* *NEW. * LPSP00L(32K 1 -drive Mm) Mod I $75.00 
LPSPOOL — Add multi-tasking to permit concurrent printing while running your 
application program The spooler and despooler obtain print |0bs from queues 
maintained by the system as print files are generated. LPSPOOL supports both 
parallel and serial printers. 

UTILITY PACKAGE (Mod II 64K) $150.00 

Important enhancements to the Mod II The file recovery capabilities alone will pay 
lor the package in even one application! Fully documented in 124 page manual! 
XHIT. XGAT. XCOPY and SUPERZAP are used to reconstruct or recover date Irom 
bad diskettes! XCOPY provides multi-file copies. Wild-card' mask select, absolute 
sector mode and other features SUPERZAP allows examine/change any sector on 
diskette include track-0. and absolute disk backup/copy with I/O recovery. DCS 
builds consolidated directories from multiple diskettes into a single display or 
listing sorted by disk name or tile name plus more Change Disk ID with DISKID 
XCREATE preailocates files and sets LOF to end to speed disk accesses DEBUGii 
adds single step, trace, subroutine calling, program looping, dynamic disassembly 
and more!' 

DEVELOPMENT PACKAGE (Mod II 64K) $125.00 

Includes RACET machine language SUPERZAP. Apparat Disassembler, and Model 
ll interlace to the M ciosott Editor Assembler Plus' software package including 
uploading services and patches tor Disk I/O E=.o»rcr J 

CHECK, vim. eve. coo. PU«CH»SE ORDER £" RACET coneuTes "^ 

TEL£PHON£0«OHS»CCEPTE0 I7UIU7SOU nin N Rlittel *■*>•«' 

•TRS 80 IS A REGISTERED !RADEM.*RK n,.'n«. TlB 

or tanov corporation Orange . C A 92665 



RACET SORTS — RACET UTILITIES — RACET computes — RACET SORTS — RACET UTILITIES — RACET computes — RACET SORTS — RACET UTILITIES — RACET computes — 
' — ™ — ~ — — — — ■■•"»■ — — ~B™fnW7NTEAMR , SE'RVIcTcAR 6™" ~ ~~~ — ~~ — ~"**^™"' 



For your 
APPLE & 

CORVUS 

Computer 

System-. 




Commercial 

Mailer _ 



Coming 
Soon on 
APPLE III! 



Store up to 

30,000 names per mailing list! 

with an unlimited number of lists! 




FEATURES OF THIS REVOLUTIONARY PROGRAM: 



Unlimited potential is available now 
with this new mailing list program de- 
signed for commercial mailers, and 
written In Applesoft. With 6 line* per 
record, fully adaptable to your format, 
up to 30,000 names can be main- 
tained on each Hat with no limit en 
the number of lists. 

PRODUCES 1UP, 2UP, 3UP, 4UP CHESHIRE OR PRESSURE SENSITIVE LABELS 
FULLY PROMPTING AND EASY TO RUN 

Available in DOS 3.2 or 3.3 



creates list 
selects list 
displays list 
reports list 



maintains list by 
zip code and 
alphabetical order 
finds entry 
browse thru entry 



change entry 
add to entry 
deletes entry 
search entries 
utility/code field 



Requirements: 

Requires 48K Apple, 80 or 132 
column printer, Corvus 11AP 
Hard Disk. Optional: Corvus 
Mirror, Corvus Constellation. 



COMPLETE SOFTWARE 
PROGRAM ONLY 

S250<"> 

Includes detailed user manual. 
Add $2. shipping. All orders pre- 
paid. NJ firms add 5% sales tax. 



"Apple" end "Corvus'' ere registered tredcmerfcs ol Apple Computer Inc. and Corvus Systems. 



STONEHENGE COMPUTER CORP. 

89 Summit Avenue 

Summit, NJ 07901 

Call (201) 277-1020 for information. 

DEALER INQUIRIES INVITED. 



AUGUST 1981 



CIRCLE 204 ON READER SERVICE CARD 
181 



_ 








YOU IN '81 &'82 

Attend the biggest public computer shows in the country. 
Each show has 100,000 square feet of display space fea- 
turing over 50 Million Dollars worth of software and hard- 
ware for business, industry, government, education, home 
and personal use. 
You'll see computers costing $150 to $250,000 including 
mini and micro computers, software, graphics, data and word 
processing equipment, telecommunications, office machines, 
electronic typewriters, peripheral equipment, supplies and com- 
puter services. 

All the major names are there including; IBM, Wang, DEC, 
Xerox, Burroughs, Data General, Qantel, Nixdorf, NEC, Radio 
Shack, Heathkit, Apple, RCA, Vector Graphic, and Commo- 
dore Pet. Plus, computerized video games, robots, com- 
\puter art, electronic gadgetry, and computer music to 
entertain, enthrall and educate kids, spouses and peo- 
ple who don't know a program from a memory disk. 
Don't miss the Coming Of The New Computers - 
Show Up For The Show that mixes business with 
pleasure. Admission is $5 for adults and $2 for chil- 
dren under 12 when accompanied by an adult. 

THE THE 

MID-WEST MID-ATLANTIC 



Ticket Information 

Send $5 per person with the name of the show 
you will attend to National Computer Shows. 
824 Boylston Street. Chestnut Hill. Mass 02167 
Tel 617 739 2000 Tickets can also be purchased 
at the show 



THE 

NORTHEAST 

COMPUTER 

SHOW 

BOSTON 
Hynes Auditorium 

PRUDENTIAL CENTER 

THURS-SUN 

OCT 15-18, 1981 

1 1 AM TO 7PM WEEKDAYS 
1 1 AM TO 6PM WEEKENDS 



COMPUTER— | 
SHOW 

CHICAGO 
McCormick Place 

SCHOESSLING HALL 
23rd & THE LAKE 

THURS-SUN 
SEPT 10-13, 1981 

1 1 AM TO 7PM WEEKDAYS 
11AMT06PM WEEKENDS 



[— COMPUTER "I 
SHOW 

WASHINGTON, DC 
DC Armory/Starplex 

2001 E CAPITAL St SE 

(ECAP ST EXIT OFF 1 295 

-KENILWORTH FRWY) 

ACROSS FROM RFK 

STADIUM 

THURS-SUN 

SEPT 24-27, 1981 

1 1 AM TO 7PM WEEKDAYS 

1 1 AM TO 6PM WEEKENDS 



THE 
SOUTHEAST 
" COMPUTER 
SHOW 

ATLANTA 
Atlanta Civic Center 

395 PIEDMONT AVE NE AT 
RALPH McGILL BLVD 

THURS-SUN 

OCT 29-NOV1, 1981 

1 1 AM TO 7PM WEEKDAYS 
1 1 AM TO 6PM WEEKENDS 



THE 

SOUTHERN 

CALIFORNIA 

COMPUTER 

SHOW 

LOS ANGELES 
LA Convention Center 

1201 SOUTH FK3UEROA 

THURS-SUN 

MAY 6-9, 1982 

1 1 AM TO 7PM WEEKDAYS 
1 1 AM TO 6PM WEEKENDS 



ting.~efffective writing 



Using Een's Compact 
Comma Calculator 

Kenneth Delp 




To comma, or not to comma— that is 
the question. That little mark of punctua- 
tion is a plague to many writers. We have 
all studied the rules, but we still get 
confused. Somehow editors and English 
teachers always seem to know where they 
go. yet we often still have the question. 
"Do I put a comma here or not?" With all 
the grammar books and usage manuals 
around, why one more explanation?' 

Maybe your experience was like mine. 
When I was in school. I was taught some 
rules about putting commas in between 
cities and states and dates and inside the 
quotation marks. There are a few other 
of these standard rules, but in sentences I 
was suposed to use a rule that went 
something like. "If you pause there, put a 
comma." 

Well, that seemed reasonable to me. so 
I did. My papers came back with my 
commas circled in red. and the teacher 
had put in little red commas in other 
places. I mentioned that I only put commas 
where I paused. She replied. "You pause 
in the wrong places." 

Somehow I learned to pause correctly. 



Kenneth Delp. 362 Tamarack Lane. Prescou. AZ 
86301. 



and that served me well until I began 
teaching English and was faced with the 
problem of telling my students that they 
paused in the wrong places. I knew that 
there had to be more sense to the comma 
rules. When I began to search the available 
grammar books. I found two problems. 

No book seemed to have all of the 
rules. There always seemed to be at least 
one or two missing. The other problem 
was that the rules were scattered through- 
out the books and clouded by mystical 
grammar terms like "introductory adverbial 
subordinate clause." I knew that my 
students would get lost in those terms. I 
also knew that they didn't have the time 
or wouldn't take the time to look on several 
different pages. So I set out to collect all 
the rules I could find, put them in one 
place, and arrange them in an easy-to-use 
format. The result is Ken's Compact 
Comma Calculator. 

I wanted the calculator to be compre- 
hensive. I wanted all the rules in one 
place. At the same time I wanted it to be 
only one page. One page, even if it was 
crowded, was more useful than several. 

After collecting rules and examples. 1 
found that they fit into only five main 
groups. These groups became the five 



basic rules of my calculator which are 
highlighted and boxed for quick reference. 
The acronym for the rules. SCIIS. can be 
remembered by the sentence: Some 
Commas /nvotve /nteresting Study. Series. 
Coordinate, /ntroductory. /nterrupting. 
Standard. 

The calculator is set up with the grammar 
rules explained in the left column and a 
correspondingly numbered example in the 
right column. The examples are not 
complicated or long. Certain real live 
sentences in writing may have more words 
or use more than one comma. But my 
examples are limited to just one kind of 
comma use per sentence. 

Many of my students have bypassed 
the grammar part. They simply make a 
reasonable assumption about which one 
of the five rules applies in a certain 
situation. Then they search the examples 
of that rule for a similar use. If you find 
the grammar too awkward or unfamiliar, 
this method works very well once you 
become familiar with the example sen- 
tences. 

Rule 1: Series 

Most people know this one. but they 
never know about the comma that goes 



AUGUST 1981 



183 



■1 



^L^H 






Reddy Chirr a improves his vision 
with an Apple. 

Reddy is an optical engineer who's 
used to working for big companies and using 
big mainframes. 

But when he started his own consulting 
business, he soon learned how costly main- 
frame time can be. So he bought himself a 
48K Apple II Personal Computer. 

And, like thousands of other engineers 







and scientists, quickly learned the pleasures 
of cutting down on shared time ^ and hav- 
ing his own tamper-proof data 

His Apple can handle 
formulas with up to 80 vari- 
ables and test parameters on 
250 different optical glasses. 

He can even use BASIC, 
FORTRAN, Pascal and Assembly languages. 

And Apple's HI-RES graphics come in 
handy for design. 

Reddy looked at other microcomputers, 
but chose Apple for its in-depth documenta- 
tion, reliability and expandability. 

You can get up to 64K RAM in an 
Apple ILUp to 128K RAM in our new Apple III. 
And there's a whole family of compatible 
peripherals, including an IEEE -488 bus for 
laboratory instrument control. 

Visit your authorized Apple dealer to 
find out how far an Apple can go with 
scientific/technical applications. 

It'll change the way you see things. 

The personal computer. CI |Df3IG 



for the dealer nearest you, call (800) 538-9696. In California, call (800) 662-9238. Or write: Apple Computer Inc., 10260 Bandley Dr., Cupertino, CA 95014. 

CIRCLE 106 ON READER SERVICE CARD 



near the "and." Most authorities say that 
it is optional unless the reader would get 
lost without it. For this reason technical 
writing usually includes it to eliminate 
any possibility of confusion. For the same 
reason most magazines and newspapers 
don't bother when there is no doubt about 
the meaning. The basic structure of the 
series remains the same no matter how 
many items there are or how complicated 
those items become. 

Rule 2: Coordinate 

Coordinate simply means equal. When 
we join two short, equal sentences with a 
conjunction (they're listed in Rule 2A), 
we put a comma with the conjunction. 
The trick here is to remember that the 
small sentence (now properly called a 
clause) on each side of the conjunction 
must have a subject (an actor) and a verb 
(an action). 

Part B of Rule 2 deals with equal 
adjectives. When these two describers are 
reversed and the meaning or sound hardly 
changes, then we include a comma. For 
example, we could write. "He was a happy, 
agreeable person." Or we could just as 
easily write. "He was an agreeable, happy 
person." Since the words are reversible, 
we include the comma to show that they're 
equal. How about. "He drove a little sports 
car"? "He drove a sports little car." just 
doesn't work. 

Rule 3: Introductory 

Rule 3 is used very frequently. The 
thinking here is simple. In a usual sentence 
the subject comes at the beginning, and 
the verb follows. However, if for some 
reason we write something in front of the 
usual sentence and we want the reader to 
suspend for a moment, we include a 
comma. We want the reader to be aware 
that there is introductory material. His 



Practice Paragraph 



Here's a paragraph where I've 
included the comma rules above the 
commas. Try them and see how they 
fit the calculator. 

In summary. 3A the AB 1400 unit is 
a quick, 2B reliable device. 2A but we 
don't like its price. Although we found 
some problems with the documenta- 
tion, 3B they were easily overcome with 
only minor revisions. The accompanying 
interface, 4E included at no extra 
cost. 4E makes the system complete. 
The printer, IA the interface, ' A and 
the unit itself are all available from 
Cactus Computer Connections, 5A 1414 
East Thirsty Circle. 5A Death Val- 
ley, 5A California. 



signal is the comma. Several grammatical 
structures fill this bill, but generally this 
thinking will handle most situations. Look 
at the examples in the calculator. 

Rule 4: Interrupting 

The comma is the mildest interruption 
of the sentence. Dashes, parentheses, and 
ellipses (a series of three dots) interrupt 
more strikingly. These interrupting commas 
normally come in pairs. They indicate 
that the "regular" sentence is interrupted 
for a moment. The first comma of the 
pair indicates a break. The second indicates 
that the interruption is complete, and the 
main sentence is continuing. 

Two notes are important. Some interrup- 
tions come at the end of the sentence. 
Obviously, in these cases there is no need 
for the second comma since the sentence 



is ended. You can see these situations in 
the second examples for A through F of 
Rule 4. 

The other point to notice is with inter- 
rupting phrases and clauses. Rules 4E and 
4F. This kind of interrupting information 
is sometimes necessary. The grammar 
description for this is called restrictive/non- 
restrictive. Rather than be that involved. 
I tell my students to think of the sentence 
without the information between commas. 
If the remaining sentence still makes good 
sense, the commas probably belong there 
telling the reader that the information is 
not absolutely necessary. 

On the other hand, if there is some 
possibility of misunderstanding due to 
incomplete information, then the commas 
should be left out. The information then 
remains an integral part of the sentence. 
Remember, this question of importance 
is for interrupting phrases and clauses 
only. 

Rule 5: Standard 

Nothing here should be a surprise. These 
rules are standard fare in all school 
classrooms. There aren't always clear 
reasons behind them other than tradition. 
Rule 5 on the calculator serves as a quick, 
clear reference for commas in standard 
places. 

Summary 

That's it. Ken's Compact Comma Cal- 
culator is designed to be a thorough but 
quick reference for comma usage. Since 
the comma is probably the most used 
punctuation mark next to the period, its 
proper use should be a consistent part of 
everyone's writing. It is a convention of 
our writing which provides clarity with 
minimal disruption of the flow of ideas. 
You can provide that clarity by referring 
to my Comma Calculator. □ 



Chas Andres 




186 



CREATIVE COMPUTING 



■■ 



copyriitht 1981 Kenneth Delp 



Ken's Compact ComimCalculatior 

DO NOT USE A COMMA UNLESS YOU HAVE A REASON 



Use commas in the following situations: 



1. between items in a SERIES . 
, , and 



A. words 

B. phrases 

C. clauses 



2. in COORDINATE situations. 

A. compound sentence with conjunction 
land, but, or, for, nor, so, yet) 

B. adjectives 

(only if they're reversible) 



I. SERIES 
(The second comma is optional except when necessary for 

clarity.) 

A. We bought chips, cookies, and pop for the picnic. 

B. You can remove the cover, adjust the drive belt, and replace 
the cover with just one tool. 

C. We cannot decide what information we will store, how we 
will retrieve it, or how it will be used. 



2. COORDINATE 

A. You must set the dial, and the ready light must be visible. 

B. It is an efficient, inexpensive unit. 



3. after INTRODUCTORY elements in sentences. 
, sentence 

A. transition word or phrase 

B. clause 

(when, if, after, since, because, etc.) 

C. noun of address 

D. interjections (mild) 

E. group of prepositional phrases 
(in, on, over, under, through, etc.) 

F. participial phrases and words 



4 to set off INTERRUPTING elements. (These commas come in 
pairs except at the end of the sentence. See the second 
examples.) 

A. parenthetical expressions 

B. nouns of address 

C. appositives 

(more specific repeaters) 

D. contrasting elements 
(opposite repeaters) 

E. phrases 

(describing but not necessary) 

F. clauses 

(describing but not necessary) 
(who, which, and that) 



.1. INTRODUCTORY 

A. First of all. I want to explain the controls. 

B. After he retyped the memo. Carl sent it to his boss. 

C. Thomas, the door is still open. 

D. Well. I didn't like the conference. 

E. In a rush of anger without a second thought, he destroyed the 
experiment. 

F. Referring to the chart, you will note the clear results of the 
research. 



4. INTERRUPTING 

part of sentence, _ 



, remainder of sentence. 



5. in STANDARD places. 

A. between parts of address and after in a sentence 



B. between parts of a date and after in a sentence 

C. to set off the direct words of a speaker 

D. in a business letter after the close 

E. in a friendly letter after the opening and the close 

F. to set off titles and after in a sentence 

G. in an alphabetic listing of names 



H. to change a statement into a question 
I. in numbers 



A. The program, admittedly, is weak in some areas. 
He will finish the project, no doubt. 

B. In some cases, Mr. Jones, this rule helps. 
Close the window, Emma. 

C. The printer, a tractor mechanism, uses a simple control. 
He bought a new car, a compact station wagon. 

D. The software, not the hardware, is the problem in this case. 
We remember our joys, not our sorrows. 

E. The printed text, displayed with or without the coding, is 
usable for editing. 

We enjoyed the new van, painted with a bright mural. 

F. The line numbers, which apply in most cases, have little value 
in this situatipn. 

We can't go to Tom's party, which will be held in a rented 

KV"- 



5. STANDARD 

A. San Francisco, California 

1000 Central Street, Dayton, Ohio 

He was born in Phoenix, Arizona, after the war. 

B. January 15, 1977 Monday, March 30, 1918 
He won the race May 17, 1903, after many years of effort. 

C. Tom said, "That is not true." 
"It is possible." said Tom. "to complete the job in an hour." 
Sincerely, 

E. Dear John, Your friend, 

F. William Phold, Jr., is the only son of William Phold. Ph.D. 

G. Clasp, Tyler 
Cloth, Terence 
Shoes, James 

H. Matilda is the boss here, isn 't she'! 
I. 1,256 421,226,500 



D. 



AUGUST 1981 



187 



fags...TflS~SO strings... TFS 



Stephen B. Gray 



For the 32nd item in this string, let's 
examine Radio Shacks Pocket Computer 
sale price of $199, a pocket computer 
newsletter, some amusing personal- 
computer messages accompanying minia- 
ture pennies, 3M's regular and special 
filters for CRT screens, a program that 
lets you run Level-I programs on a Level- 
II machine, three programs (opera music, 
keyboard organ, games for children) from 
TSE Ramworks, and a short program to 
help pack your strings. 

Pocket Computer "Sale" 

A Radio Shack ad in the April 26, 1981, 
New York Times offered the TRS-80 
Pocket Computer at $199, or $50 off the 
regular $249 price. Price reductions on a 
dozen other items, mainly hi-fi, were offered 
for a week, as "Grand Opening Specials," 
celebrating four new Radio Shack stores 
in the New York area. 

A later Radio Shack ad in the New 
York Times, in May, offered the Pocket 
Computer at $199, for the month of May 
only, in celebration of Radio Shack's 60th 
anniversary. 

In a Radio Shack ad in the May 21 
Times: "First Time on Sale! The TRS-80 
Pocket Computer," at $199. for a week 
only. 

In May, a Radio Shack executive said, 
"After the end of May the price may 
never be this low again." 

By the time you read this, the price 
may still be at $199. Radio Shack cut the 
price because Sharp Electronics Corp. 
(which manufactures the Pocket Computer 
and which gave Radio Shack an exclusive 
for a limited time) started selling it in 
May as the PC-1211, under the Sharp 
label. 

A full-page Sharp ad in the May IEEE 
Spectrum magazine for "A Real Computer 
You Can Put in Your Pocket" doesn't 
mention the price, which was then $249. 
A Sharp executive told me, in May, that 
his company "has no plans to drop the 
price of the PC-1211; they're selling like 
hotcakes." 

Also available in May was the Sharp 
CE-122, a combination printer and cassette 
interface at $150, looking very much like 
Radio Shack's cassette interface, but with 



a very small printer at its left end, using 1 
1/2-inch paper. Sharp says they also have 
a CE-121 cassette interface, at $50, which 
is the same as the Radio Shack interface, 
at $49. 

Sharp has three manuals for the PC- 
1211: an instruction manual, a Basic 
manual, and an applications manual with 
125 (some say 137) programs. More on 
those after I see them. 

The only difference between the two 
computers, other than the logos, seems to 
be that the Radio Shack Pocket Computer 
uses three batteries, while the Sharp PC- 
1211 uses four. 

Pocket Computer Newsletter 

A Pocket Computer Newsletter has been 
published since late 1980 by Nat Wads- 
worth, founder of Scelbi Publications 
(which offers books on assembly language. 
Basic, microcomputers, graphics etc.). 

The newsletter is advertised as containing 
"news and product reviews, programming 
tips, operating timesavers, tutorials, short 
cuts, practical programs, technical details " 
etc. 

The first five issues deal almost entirely 
with the Radio Shack TRS-80 Pocket 
Computer, the only pocket computer 
available during the period covered. 
Perhaps by the time you read this, others 
will be on the market. 

Among the articles in the first five issues 
are programs for a memo pad, an alarm 
clock, tax calculations, estimating and 
billing, decimal-to-hex conversions, tic-tac- 
toe, and a numerical sort; reviews of the 
Radio Shack business financial program 
and Games Pack I; an item about the 
Panasonic/Quasar Hand Held Computer, 
a discussion of the nine interfacing pins 
on the cassette interface, several operating 
tips, and a programming form for the PC. 

One of the operating tips is: "When 
editing numeric expressions or anything 
not enclosed by quotation marks, it is 
quicker to use the SPC key than the SHIFT 
DEL keys. When you hit the ENTER key 
the interpreter will remove any unnecessary 
spaces!" 

For 20 issues of the newsletter, send 
$20 (In Canada, $24), to Pocket Computer 



Newsletter, Box 232, Seymour, CT 
06483. 

My Total Profits 

A California entrepreneur has a clever 
gimmick: a tiny copper-clad replica of a 
Lincoln penny, 5/16 inch in diameter, 
mounted on cards bearing messages. 
They're sold "to the gamblers in Nevada 
and Atlantic City, and to the poor tax- 
payer" the letter says. 

With the help of Paul Raymer. of Paul's 
Electric Computer, a Las Vegas software 
company, a dozen messages relating to 
personal computers were devised. 

The messages range from "My total 
profits on programs I've written" to "My 
share of America's $100 million computer 
market," and also include "My change 
from a $20 bill after visiting a computer 
store," "My hourly rate as a computer 
programmer" and "Money I've saved doing 
my own programming." Several thousand 



MY TOTAL 
PROFITS 



ON PROGRAMS 
I'VE WRITTEN 



Figure I. 

have been sold "through selected computer- 
store dealers to date," the letter says. 

Each mini-coin sells for about 50 cents 
(suggested list). A sample is 50 cents, but 
Mark Michael of BPC has kindly offered 
to provide 100 free assorted computer 
mini-coins to the first 100 readers of 
Creative who ask for one, and specify 
that they read this column. Send a self- 
addressed stamped envelope to Boardwalk 
Products Co., Box 74157, Los Angeles 
CA 90004. K 

Other mini-penny messages are available, 
including "My bonus," "My gambling 
winnings," and "My life savings.'The best 



188 



CREATIVE COMPUTING 



; 




PRESENTS ACTION GAMES BY JOHN ALLEN 
NEW! 






MiMtLtl 



By John Allen 

John Allen works his machine language magic 
again! With the realistic action and sounds 
made famous by his bestselling "PINBALL" 
and "BASKETBALL" arcade games, TENPINS 
now brings all the thrills of championship 
bowling to yourTRS-80* model I or III. 

From one to four players participate, and the 
program automatically senses the skill of 
each player. Beginners can simply position 
the ball and "roll" it while more skilled players 
can vary the force, roll a curve, and cause it to 
spin as it heads for the pins. All this— plus 3-D 
graphics and sound effects— adds up to a 
realistic and thoroughly challenging bowling 
game. 

Scoring, pinsetting and ball return are all auto- 
matic, and you can view the entire scoresheet 
at any time. TENPINS even has factors to sim- 
ulate the imperfections found in bowling 
lanes, adding even more realism— and some- 
times frustration— to the game. It's almost as 
hard to roll a perfect 300 score in TENPINS as 
it is in real bowling, but it sure is fun trying! 
Available for only $14.95 for 16K tape version, 
$20.95 for 32K disk. 



By John Allen 

Get your flipper fingers ready for action in this 
real-time, machine language game. 

Lots of sound and flashing graphics make this 
fast action game so much like the real thing 
that you'll have to remind yourself not to 
shake yourTRS-80*. Choose from five playing 
speeds to match your skill— but be prepared 
for a lot of practice if you ever hope to master 
the fastest speed. 

Can you beat your friends' scores? Will you 
avoid the dreaded "Bermuda Square?" Get 
PINBALL today and find out. Available for 
model I and III, $14.95 on tape or $20.95 on 
disk. 



a^aKsina^ 




By John Allen 



Fast machine language action game, with 
sound, from the author of the acclaimed 
"PINBALL"! 

Try to keep up with the action and outscore 
your opponent in five minutes of one-on-one 
basketball. Steal the ball, duck around your 
opponent and slant toward the basket for a lay 
up! The graphics are based on a 3-di mensional 
depiction of a basketball court, and ball drib- 
bling sounds add to the realism. Compete 
against a friend or your computer. 

It's all there but the cheers— for model I and III 
on tape for only $14.95, disk version for $20.95. 



Available now from Acorn dealers everywhere 



AUTHORS * DEALERS WANTED 




•"• 



n 



Software Products, Inc. 

(202) 544-4259 
634 North Carolina Avenue, S.E . Washington, DC 20003 



ALL ACORN 

ENTERTAINMENT SOFTWARE 

IS NOW AVAILABLE FOR 

TRS-80* MODELS I & /// I 



* TRS-80 is a trademark ot Tandy Corp 



CIRCLE 101 ON READER SERVICE CARD 



TRS-80, continued. 




Figure 2. CRT filler. 



seller is "Tip for lousy service." Mini- 
nickels are mounted on Cash Award 
Certificates for "Greatest boss," "Jackpot 
winner," "Disco dancer," etc. 



3M CRT Filters 

In the ads for CRT filters that occasion- 
ally grace the pages of this and similar 
magazines, the benefits are listed as 



improved image contrast, reduced eye 
fatigue, enhancement of screen legibility, 
decreased glare, giving the system a 
professional look, etc. 

The most important seems to be decreas- 
ing the glare, one of the "ergonomic" 
factors often mentioned in articles about 
office-of-the-future terminals. In many 
installations, typewriters have been 
replaced with CRT terminals by simply 
removing one and installing the other, 
without checking out factors such as 
keyboard height, ease of document 
handling, and glare from nearby windows 
or other light sources. 

3M's Data Recording Products Division 
has a variety of filters which they call 
films; well look at two of them. The Panel 
Film "selectively filters ambient room light, 
enhancing the CRT image by reducing 
glare," according to the press release. 

The Light Control Film has, in addition, 
a horizontal "microlouver" construction 
that "limits the vertical angle from which 
the face of the terminal screen can be 
read, enhancing its confidentiality." A 
person standing behind a CRT terminal 
operator would have a very hard time 
trying to read the screen through this 
filter. 

A Light Control Film, rotated 90 degrees, 
might be ideal for classroom use. to prevent 




LET YOUR APPLE SEE THE WORLD! 

The DS-65 Oigisector' opens up a whole new world for your Apple II. Your computer 
can now be a part of the action, taking pictures to amuse your friends, watching your 
house while you're away, taking computer portraits ... the applications abound! The 
DS-65 is a random access video digitizer. It converts a TV camera's output into digital 
information your computer can process. The DS-65 features: 

• High Resolution — a 256 x 256 picture element scan 
• Precision — 64 levels of grey scale 
Versatility — Accepts either NTSC or industrial video input 
Economy — A professional tool priced for the hobbyist 

The DS-65 Is an intelligent peripheral card with onboard software in 2708 EPROM. 
Check these software features: 

• Full screen scans directly to Apple Hi-Res screen 

• Easy random access digitizing by Basic programs 

• Line-scan digitizing for reading charts or tracking objects 

• Utility functions for clearing and copying the Hi-Res screen hires PICTURE USING THE DS-65 

AND PICTURE SCANNER SOFTWARE 

Use the DS-65 for precision security systems; computer portraiture; robotics; fast to slow scan conversion; moving target indicators; 
reading UPC codes, musical scores and paper tape and more! GIVE YOUR APPLE THE GIFT OF SIGHT! DS-65 Price: $349.95 / FSII 
Camera Price: $299.00 / Combination Price: $599.00 

ADDITIONAL SOFTWARE FOR THE DS-65 
—Picture Scanner Provides a variety of different dithering algorithms for compressing the digitized image into the Hi-Res 
screen. Available on 13-sector disk. Price: $39.95 

— Superscan: Enables you to enhance the DS-65's Hi-Res pictures with colors! Choose from 21 different colors and assign them 
to grey scale values, modify pictures, zoom, enhance contrast, etc. Print routines for the Anadex and Paper Tiger' are provided 
Comes on a 13-sector disk. Written for The Micro Works by Magna Soft. Price: $79.95 

—Portrait System Software: This program includes captions and a credit line, reverse printing for T-shirt application and the 
option to save portraits on disk. Specifically for use with a Malibu 165 printer. Call or write for more information. 

THE /\/"V PI /?^ I "\ /Z>\ "Paper Tiger is ■ trademark of Integral Data Systems, Inc. 

ZA_a\ U vSr Lrv^Q/ MasterCharge/Visa Accepted 

\ffi@[JS5SJ? P.O. BOX 1110 DEL MAR, CA 92014 714-942-2400 




CIRCLE 212 ON READER SERVICE CARD 



190 



CREATIVE COMPUTING 



COLOR COMPUTER OWNERS! 
CLOAD INC. ANNOUNCES 



CHROMASETTE MAGAZINE! 

A monthly magazine-on-cassette for your 
Extended BASIC Color TRS-80! 




Put a rosy color in you and 
your computer's checks, 
stop reading these old 
cliches, and get a subscrip- 
tion to CHROMASETTE 
Magazine. 

Plcu.sc Write for Foreign Kates 
and other into. 



Goleta California — With 
CHROMASSETTE 

Magazine, Color Com- 
puter owners can now enjoy 
the variety, economy, and 
easy entry of programs that 
(LOAD subscribers have 
enjoyed lor 3 years. 

CHROMASETTE 

Magazine gets rid of the 

type-in-and-edit blues by 

putting a rainbow of ready-to-load programs on 

cassette, and sending them to you by Hirst Class 

Mail each month. Educational, practical, utility. ChromaSCtte Magazine 

and game programs are delivered right to your RO. BOX 1087, Santa Barbara, CA 93102 

mailbox 805 963-1066 

CIRCLE 111 ON READER SERVICE CARD 



CIIROUASI III MafKiHt in us Prime Sum- 



$45.00 year. $25.00 (> 
months. $5.00 single issue, or 
Send u HI. ink (heck und your 
account balance. Visa and 
MasterCard also accepted. 



CLOAD MONTHLY 



"all the fit that's news to load' 



TRS-80 PROGRAMS ON CASSETTE 



CLOAD Magazine for your Model I or III 



Goleta. C'alil You can gel 7 or X programs on cassette, each month, 

thai ('LOAD directly into youf TRS-80 Model I or III! 

A subscriber, loo engrossed in Irving to save the world from invading 
aliens (March. I9KI issue! to give his name, staled. "I receive a 30 minute 
cassette by lirst Class Mail each month containing some of the besl games 
and educational programs I have ever played. Some are even in machine 
language! "Another ('LOAD subscriber. Claudine C'load. could now 
"lit the computer into her schedule" thanks to the utilities and occasional 
disk programs she received from (.'LOAD. She was writing about it lo all 
ol the people Otl her mailing list (November. Is>7" issue) 
Get the news firsthand. Gel a subscription to ('LOAD Maga/me. 



by Clyde (load, star reporter 



The Fine Print: 

Overseas rates slightly higher — 

please wnte tor them. 
Back issues available— ask for our list * 
TRS-80 is a trademark ot Tandy Corporation 
California residents add 6* lo single copies 
and anthologies. Programs are for Level II 
I6K, Model III I6K . and occasionally for disks 

*24 Level I back issues also available. 



PRICES 

I year subscription *42.00 

6 month subscnption .... $23.00 

Single copies *4 bO 

Anthology volume I .... * 1 00 
Anthology volume 2 .... * 1 5.00 

Mastercard Visa Welcome. 



MAGAZINE INC. 

RO. Box 1448, Santa Barbara, CA 93102 

CIRCLE 113 ON READER SERVICE CARD 




805 962-6271 



01961 



TRS-80, continued... 

students from peeking at adjacent screens 
during exams. 

Glare reduction by both films is said to 
be equivalent to that of a 14-inch top 
hood on the terminal. The filters are 
applied, preferably on the inside of the 
terminal cabinet, with adhesive or double- 
sided tape. The filters aren't flat, but are 
formed to the standard radius of all CRT 
faces. Other standard diagonal-measure 
sizes are five, nine and 15 inches. 

The 12-inch diagonal-measure filters, 
which fit the Model I. II and III TRS-80s. 
have suggested list prices of $20.55 each 
for one to 10, and $19.50 for 11 to 20 of 
the Panel Films; $38.90 for one to 10 and 
$36.95 for 11 to 20 of the Light Control 
Films. 

These filters advertised in personal- 
computer magazines cost considerably less 
than $20.55 each, more like $13.95 or 
even $7.95. However, the couple I've seen 
at those prices were flat and rectangular 
with rounded comers, and are also curved 
convexly to fit as closely as possible to 
the screen, for maximum legibility. 

If you use a computer CRT for any 
appreciable length of time, you may find 
that a filter helps cut eyestrain fatigue. 

Level-I in Level II 

This program, previously available from 
Apparat, is a $14.95 16K Level-II program 
now marketed by TSE/Hardside, for 
running Level-I programs on a Level-II 
machine, or for making Level-I-compatible 
tapes on it. 

Long ago I'd made up a tape of some 
Level-I graphics programs, and wanted to 
find out what they were. With the conver- 
sion program, I was able to load in the 
graphics programs. LIST and RUN them. 
(They can also be CSAVEd.) However, 
when I tried to LLIST one to a printer, I 
got WHAT? because there's no LLIST 
command in Level-I. 

If you use Radio Shack's old "Program 
Conversion Level-I to Level-H" tape (which 
isn't listed in any catalog, but which I 
believe used to be shipped with Level-II 
machines), you can LLIST the programs 
to a printer. But you have to convert the 
Level-I programs one at a time, running 
the conversion program each time you 
want to convert. Whereas, with the TSE 
program, you can CLOAD a program, 
LIST and/or RUN it, and then CLOAD 
the next one, right away. 

Incidently, when I couldn't find the file- 
names for these two conversion tapes 
anywhere, I ran the one-line program given 
in Short Program #20 at the end of this 
column, and got the names I needed to 
load them: LEVEL1 and CONV. 

Programs can be edited under the Radio 
Shack conversion program, but not under 
the TSE program, with which you're still 
in Level-I, which has no editing facilities. 



Selected V»v.l«n 8 lh 




Selected Wi w ltogltl 




Lijht Control Film 



VDT 



Figure 3. 3M"l Panel Film (left) transmits only selected wavelen K ths emitted by the electronic display 

itself, thus enhancing the contrast ratio. The Li K ht Control Film (rinhtl has. in addition, a "microlouver" 

instruction designed for maximum lii'hl .-.mrr.,1 rtmiAAin., ....n,.. .....CI,.. :.,i:... r • _ 



iisin. mus cnnancinu me contrast ratio. I he Lmht Control Film IriKhtl has. in addition, a "microlouver" 
construction designed for maximum lixht control, providing, some confidentiality for computer-terminal 

users. 



Three From TSE Ram works 

TSE/Hardside, which markets a variety 
of software (and hardware) from outside 
sources (as well as publishing SoftSide 
magazine), also offers some of its own 
programs, under the Ramware name. 

Let's look at three Ramware programs— 
Opera Theater, Keyboard-80, and Nine 
Games- from TSE/Hardside (6 South St., 
Milford, NH 03055). 

Opera Theater 

Listed in the catalog as "Opera Theater" 
and labelled on the 16K Level-II cassette 
as "TRS-80 Opera," this $9.95 Ramware 
item is more a demonstration of how much 
can be done with a monophonic music 
composer, than as musical treats for opera 
lovers. 

Since the basic waveforms used for this 
music are quite simple, without the variety 
of overtones that give musical notes their 
character, the best way to dazzle the ears 
with music composers that can generate 
only one note at a time, is to play rapid 
passages of short notes. 

This gives the illusion that several notes 
are heard at the same time, and/or that a 
virtuoso performer is playing complex pas- 
sages with great skill, speed and 
accuracy. 

The best example on this cassette is 
Rossini's William Tell Overture, performed 
with dazzling speed and with rapid 
arpeggios that seem to sound two and 
sometimes even three notes simulta- 
neously. 

The other four pieces are played at 
various tempos, but all include fast passages 
or arpeggios that sugest polyphonic music: 
"Sempre Libera" from Verdi's La Traviaia, 
"Musetta's Waltz" from Puccini's La 
Boheme. "Queen of the Night" aria by 
Mozart, and "La Donna e' Mobile," from 
Verdi's Rigoletto. 



Two of the opera selections are played 
too fast. However, the main point here is 
not the music, but a demonstration of 
programming skills with a monophonic 
music composer, and as such, this is a 
winner. 

Try to LIST this, by the way, and you 
get a very strange mixture of meaningless 
characters, string packing and Basic lines, 
and message: 

AS YOU SEE, THIS PROGRAM DOES 
NOT TAKE WELL TO LISTING. 

Keyboard-80 

For $9.95, the Keyboard-80 cassette 
"magically transforms" your 16K Level-II 
TRS-80 keyboard "into a three-octave 
organ," according to the small 12-page 
manual, which is mainly a "song sheet," 
with six tunes provided in keyboard nota- 
tion. 

To hear the music, plug the AUX cable 
from the computer into an audio-amplifier 
input. 

Keys Z-M give you most of the first 
octave, keys A-J provide most of the 
second, and keys O-I give the top octave. 
If you're a touch-typist, you'll have no 
trouble playing any of the six tunes provided 
in the manual. However, you'll have to 
figure out the rhythm yourself. 

The keys provide only "white notes," 
without black-note sharps or flats, so there's 
a limit to what you can play with Keyboard- 
80. The "Happy Birthday" provided by 
the manual is in F: 

AASAFD 

AASAGF 

A AQHFDS 

HHHFGF 
so the first two H's in the last line, which 
should be B-flat, are actually B, so the 
tune sounds wrong at that point. If it had 
been written in C, no flats would have 
been required. The other tunes haven't 



192 



CREATIVE COMPUTING 



4MHZ, DOUBLE DENSITY.COLOR&B/W 
GRAPHICS . .THE LNW80 COMPUTER 




dhen you've compared the features of an LNW80 Computer, you'll quickly 
understand why the LNW80 is the ultimate TRS80 software compatible system. 
LNW RESEARCH offers the most complete microcomputer system at an outstand- 
ing low price. 

Me hack up our product with an unconventional 6 month warranty and a 10 
days full refund policy, less shipping charges. 

LNH80 Computer $1 ,450.00 

LNW80 Computer w/BIU Monitor 1 one 5" Drive $1,914.00 

All orders must be prepaid. CA residents please include 61 sales tax. 
Contact us for shipping charges 

* TRS80 Product of Tandy Corporation. 

** PMC Product of Personal Microcomputer, Inc. 



COMPARE THE 
FEATURES 


FEATURES AND PERFORMANCE 

LNM80 PHC-80" 


TRS-80* 
MODEL III 


PROCESSOR 




4.0 MHZ 


1,1 mi 


2.0 MHZ 


LEVEL 11 BASIC INTERP. 




YES 


YES 


LEVEL III 
BASIC 


TRS30 MODEL 1 LEVEL II COMPATIBLE 


YES 


YES 


NO 


48K BYTES RAH 




YES 


YES 


YES 


CASSETTE BAUD RATE 




500/1000 


500 


500/1500 


FLOPPY DISK CONTROLLER 




SINGLE/ 
DOUBLE 


SINGLE 


SINGLE/ 
DOUBLE 


SERIAL RS232 PORT 




YES 


YES 


YES 


PRINTER PORT 




YES 


»ES 


YES 


REAL TIME CLOCK 




YES 


YES 


YES 


24 X 80 CHARACTERS 




YES 


NO 


NO 


VIDEO MONITOR 




YES 


YES 


YES 


UPPER AND LONER CASE 




YES 


OPTIONAL 


YES 


REVERSE VIDEO 




YES 


NO 


NO 


KEYBOARD 




G3 KEY 


S3 KEY 


53 KEY 


NUMERIC KEY PAD 




YES 


NO 


YES 


B/U GRAPHICS, 128 X 48 




YES 


YES 


YES 


HI-RESOLUTION B/W GRAPHICS. 


180 X 192 


YES 


NO 


NO 


HI-RESOLUTION COLOR GRAPHICS 
128 X 192 IN 8 COLORS 


(NTSC). 


YES 


NO 


NO 


HI -RESOLUTION COLOR GRAPHICS 
384 X 192 IN 8 COLORS 


(RGB). 


OPTIONAL 


NO 


NO 


WARRANTY 




6 MONTHS 


90 DAYS 


90 DAYS 


TOTAL SYSTEM PRICE 




S 1 , i 1 4 . 00 


$1, 840.00 


t2.187.00 


LESS MONITOR AND DISK DRIVE 




$1 ,450.00 


Jl.375.00 


... 



LNW80 

- BARE PRINTED CIRCUIT BOARD i MANUAL J89.95 

The LNW80 - A high-speed color computer totally compatible with 
the TRS-80*. The LNU80 gives you the edge in satisfying your 
computation needs in business, scientific and personal computa- 
tion. With performance of 4 MHz, Z80A CPU, you'll achieve per- 
formance of over twice the processing speed of a TRS-80*. This 
means you'll get the performance that is comparable to the most 
expensive microcomputer with the compatibility to the world's 
most popular computer (TRS-80*) resulting in the widest soft- 
ware base. 



FEATURES: 



TRS-80 Model 1 Level II Software Compatible 

High Resolution Graphics 

. RGB Output - 384 x 192 in 8 Colors 

. NTSC Video or RF MOO - 128 x 192 in 8 Colors 

. Black and White - 480 x 192 

4 MHz CPU 

500/1000 Baud Cassette 

Upper and Lower Case 

16K Bytes RAM. 12K Bytes ROM 

Solder Masked and Silkscreened 



LNW SYSTEM EXPANSION 

BARE PRINTED CIRCUIT BOARD 

AND MANUAL J69.95 

WITH GOLD CONNECTORS $84.95 

The System Expansion will allow you to expand your LNW80. TRS-80* 
or PMC-80** to a complete computer system that Is still totally 
software compatible with the TRS-80* Model 1 Level II. 



LNDoubler&DOS PLUS 3.3D 

Absent) led and Tested w/DOS PLUS 3. 3D $1 75. 00 

Double- density disk storage for the LNW Research's "System Expan- 
sion" or the Tandy's "Expansion Interface". The LMDoubler™ Is 
totally software compatible with any double density software 
generated for the Percom's Ooubler***. The LNDoublerTM provides 
the following outstanding features. 

Store up to 350K bytes on a single 5" disk 
Single and double density data separation 
Precision write precompensation circuit 
Software switch between single and double density 
Easy plug in installation requiring no etch cuts, jumpers 
or soldering 
. 35. 40, 77, 80 track 5" disk operation 
120 day parts and labor Warranty 

»** Ooubler Is « product of Percom Data Company. Inc. 

DOS PLUS 3.30 

Micro Systems software's double density disk operating system. 
This operating system contains all the outstanding features of 
a well developed DOS, with ease in useabllity. 

KEYBOARD 

LNW80 KEYBOARD KIT $84.95 

The Keyboard Kit contains a 63 key plus a 10 key. P.C. board, and 
remaining components. 

CASE 



32K Bytes Memory 

5" Floppy Controller 

Serial RS232 20ma I/O 

Parallel Printer 

Real Time Clock 

Screen Printer Bus 

On Board Power Supply 

Solder Masked and Silkscreened 



LNW RESEARCH 



OR P O R A T I 
2620 WALNUT 
TUSTIN CA. 92680 



O N 



LNW80 CASE $84.95 

The streamline design of this metal cast will house the LNW80, 
LWN System Expansion, LNU80 Keyboard, power supply and fan. 
LNDoublerTM, or LNW Data Separator. This kit Includes all the 
hardware to mount all of the above. Add $12.00 for shipping 

PARTS AVAILABLE FROM LNW RESERARCH 
4115 - 200ns RAM 

5 chip set $26.00 

8 chip set $33.50 

16 chip set $64.00 

24 chip set $94.00 

32 chip set $124.00 

. LNU80 "Start up parts set* LNW80-1 $82.00 

. LNW80 'Video parts set* LNW80-2 $31.00 

. LNW80 Transformer LNW80-3 $18.00 

. LNWSO Keyboard cable LNW80-4 $16.00 

40 Pin computer to expansion cable $15.00 

System Expansion Transformer $19.00 

. Floppy Controller (FD1771) and UART (TRI602J . . . $30.00 



ORDERS A INFO NO 714 544 5744 
SERVICE NO. 714-641 -8850 



CIRCLE 27S ON READER SERVICE CARD AC CEPTED 



VISA MASTER CHARGE 



UNLESS NOTED 

ADO $3 FOR SHIPPING 



Special editions for Apple, 
Atari and TRS-80 Computers. 



^v /; 




Hey kids, are the folks out of the room'' 
Good, cause I ve got a secret to tell you 
You know that computer they fuss over'' 
Well. kid. between you and me. this whole 
programming thing is a lot simpler than 
they realize 

Whats that? Sure, you can learn Just 
get a copy of Computers For Kids. It's a 
super book, and it tells you everything you 
need to know Huh? You have an Apple'' 
No problem There's a version just for the 
Apple One for the TRS-80 and one for the 
Atari too, with complete instructions for 
operating and programming 

The book will take you through every- 
thing programmers learn Its easy to 
understand and the large type makes it 
easy to read You II find out how to put 
together a flowchart, and how to get your 
computer to do what you want it to do 
There s a lot to learn, but Computers For 
Kids has 12 chapters full of information 
You II even learn how to write your own 
games and draw pictures that move 

Just so the folks and your teachers won t 
feel left out. there s a special section for 
them It gives detailed lesson ideas and 
tells them how to fix a lot of the small 
problems that might pop up Hey. this 
Dook is just right for you But you don t 



have to take my word on that Just listen to 
what these top educators have to say 
about it: 

Donald T. Piele. Professor of Mathe- 
matics at the University of Wisconsin- 
Parkside says. Computers For Kids is the 
best material available for introducing stu- 
dents to their new computer It is a perfect 
tool for teachers who are learning about 
computers and programming with their 
students. Highly recommended ' 

Robert Taylor, Director of the Program 
in Computing and Education at Teachers 
College. Columbia University states, it's a 
good idea to have a book tor chidren." 

Not bad. huh? Okay, you can let the 
adults back in the room Don't forget to tell 
them Computers For Kids by Sally 
Greenwood Larsen cost only $3 95 And 
tell them you might share it with them, if 
theyre good Specify edition on your 
order: TRS-80 (12H); Apple (12G): Atari 
(12J). 

Your local computer shop should carry 
Computers For Kids If they don t ask 
them to get it or order by mail Send S3. 95 
payment plus $2 00 for one. $3 00 for two 
or more for shipping and handling to 
Creative Computing Press. PO Box 789- 
M. Morristown. NJ 07960 



creative computing ppess 

CIRCLE 350 ON READER SERVICE CARD 



TRS-80, continued... 

any problems with flats or sharps; 
"Marianne," "Battle Hymn of the Republic," 
"When the Saints Go Marching In," etc. 

The organ is monophonic, playing only 
one note at a time. But with a little dexterity 
and fast arpeggio-playing with two or three 
fingers, you can create the illusion of 
almost-chords. 

For that $9.95, though, you don't get 
much. For $14.95 you can get ORGAN 
(Sept. 1980. p. 188) from Micropute 
Software (Box 1943. Rock Mount, NC 
27801 ). This 4K Level II program provides 
a two-manual, three-octave organ, with 
sharps and flats. And if you press two or 
three keys simultaneously, you get a 
warbling effect, as the notes alternate. 

Also, you can change from loud to soft 
and back, from a clear tone to a nassal 
sound and back, and provide a range of 
tremolo and timbre values. As a bonus, 
the keyboard is displayed on the screen, 
and when a key is depressed, an asterisk 
appears on the corresponding displayed 
organ key. 

Nine Games for Pre-Scbool Children 

George Blank. Creative 's editorial 
director, who may be familiar to some of 
you as author of such complicated action 
games as Clipper, Santa Paravia & 
Fiumaccio, and Pork Barrel, turns his 
attention in this $9.95 16K Level-II collec- 
tion to simpler games, for younger users. 

All nine programs are run in doible- 
width characters, for easier reading. The 
author, in the forward to the very brief 
11-page manual, says he's taught four- 
year-olds how to use the programs in IS 
minutes. They learned to press a number 
to take them from the menu to the desired 
program, to press CLEAR to stop a 
program or to change programs, to type 
RUN and press ENTER, and to press 
ENTER and try CLEAR again if the screen 
goes blank when they press CLEAR. 

LETTERFUN uses the screen as a 
blackboard. The child enters letters or 
numbers until a control character such as 
ENTER is pressed. Then the word or 
phrase is repeated across or down the 
screen, or moved around the screen, or 
broken up and scattered around. The 
object of the game, the manual says, is to 
"increase letter recognition, pattern dis- 
crimination, and interest in words." 



"The computer can be welcomed as one 
of our most promising forward steps. And 
if we fail to use the new opportunities 
which it offers us, let us at least be honest 
with ourselves. Let us then admit that it 
was man, and not the machine, that let 
men down. " 

John R. Coleman 



194 



CREATIVE COMPUTING 






ABC requires the child to type the 
alphabet in the correct order. Each correct 
letter makes an inch-high face smile; each 
wrong one makes the man shake his 
head. 

LETTER WARS provides "practice in 
associating the large lower-case letters on 
the screen with the upper-case letters on 
the keyboard." This game is best played 
in a group. After ten letters are displayed, 
a space-battle ensues, with hits and counter- 
hits that indicate the child's score, which 
is then displayed as a percentage. 

REPEAT simply fills a 32-character row 
with any character pressed, and is designed 
to "deliberately develop pattern recognition 
to prepare children for word recognition 
and art." 

NAMES requires that an adult enter 
six names, and the computer then selects 
them at random and prints them in groups 
of 50. "This is also good practice for 
beginning readers to learn new words." 

BLACKBOARD simply uses the screen 
as a 32-character-per-line blackboard, with 
the left-arrow acting as an eraser. 

TROLL'S GOLD is a chase through a 
maze in which doors open and close at 
random. The child waits for the right door 
to open, presses an arrow key, and heads 
toward the pile of gold, door by door, and 
tries to get back to the starting place and 
up the stairs without getting caught and 
eaten by the troll. "The game teaches 
direction and eye-hand coordination." 

MATH DRILL presents both numbers 
(for children who can read them) and 
graphics blocks (for children who haven't 
yet learned their numbers), and provides 
drills in addition and subtraction. The 
numbers to be added or subtracted don't 
go above nine, and subtraction doesn't 
result in a negative number. 

CALCULATOR provides the four basic 
functions, with the difference that the 
display is in the form that children use in 
school, with numbers placed vertically 
above a line for addition, subtraction and 
multiplication, and within or to the left of 
the inverted L-sign for division. 

The nine games combine fun with 
learning, are written to make playing them 
as easy as possible, and I wish my children 
had had the use of them before going to 
P.S. 9, because some subjects might have 
been made easier with these games. 

TSE/Hardside/Ramworks programs 
come with an Order Adjustment Form 
that asks if something is wrong, or missing, 
or broken, and if so, asks the purchaser 
to fill in the form, call for an authorization 
number, and return of the invoice along 
with the wrong or broken item. Sounds 
very efficient. 

Short Programs #20 And #21 

Here's a letter I should have used last 
year, from James A. Lisoswki of the 



HOW TO START YOUR 
OWN COMPUTER 
BUSINESS 



Microcomputers today offer better opportunities to the small entrepreneur than any other in- 
dustry If you are looking for more than a 9 to 5 job for the rest of your life, the time to act is now. 
The HOW TO manuals from Essex Publishing will help you with facts and step by step guid- 
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computer hobbyists. 



& 



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$36. 



HOW TO START VOUR OWN SYSTEMS HOUSE 

6th edition. March 1960 

Written by the founder ol a successful systems house, this 

fact-filled 220-page manual covers virtually all aspects of 

starting and operating a small systems company It is abundant 

with useful, real-life samples contracts, proposals, agreements 

and a complete business plan are included in full, and may be 

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Proven, field-tested solutions to the many problems facing the 

small systems house are presented 

From the contents 

• New Generation of Systems Houses • The SBC Marketplace 

• Marketing Strategies • Vertical Markets & lAPs • Competitive 
Position/Plans of Maior Vendors • Market Segment Selection & 
Evaluation • Selection of Equipment & Manufacturer • Make or 
Buy Decision • Becoming a Distributor • Getting Your 
Advertising Dollar's Worth • Your Salesmen Where to Find 
Them • Product Pricing • The Selling Cycle • Handling the 12 
Most Frequent Obiections Raised by Prospects • Financing for 
the Customer • Leasing • Questions You Will Have to Answer 

No. 10 Before the Prospect Buys • Producing the System • Installation. 
Acceptance. Collection • Documentation • Solutions to the 
Service Problem • Protecting Your Product • Should You Start Now? • How to Write a Good 
Business Plan • Raising Capital 



COMPUTER 
CONSULTANT 



HOW TO BECOME A SUCCESSFUL COMPUTER 
CONSULTANT 

by Leslie Nelson. 2nd revised edition. Jan 1981 
Independent consultants are becoming a vitally important factor 
in the microcomputer field, filling the gap between the computer 
vendors and commercial/industrial users The rewards of the 
consultant can be high freedom, more satisfying work and 
doubled or tripled income HOW TO BECOME A SUCCESSFUL 
COMPUTER CONSULTANT provides comprehensive back- 
ground information and step-by-step directions for those 
interested to explore this lucrative field 

• Established consulting markets • How to get started • Itemized 
start-up costs • Are you qualified? • Beginning on a part-time 
basis • The Marketing Kit • Should you advertise? • Five 
marketing tips • Getting free publicity • How much to charge 

• When do you need a contract? • Sample proposals • Which 
$28. No. 16 jobs should be declined • Future markets • The way to real big 

money • Avoiding the legal pitfalls • How consultants' associations can help you • The National 
Register ol Computer Consultants • How others did it real-life sample cases • and much more 




FREE-LANCE SOFTWARE MARKETING 3rd edition. June 1980 
Writing and selling computer programs as an independent is a 
business where • you can get started quickly, with little capital 
investment • you can do it full time or part time • the potential 
profits are almost limitless Since the demand for computer 
software of all kinds is growing at an explosive rate, the 
conditions for the small entrepreneur are outstanding 

This manual will show you how to sell your own computer programs 
using these proven techniques • direct to industries • through 
consulting firms • through manufacturers of computer hardware 
• in book form • mail order • through computer stores It will 
show you how to profitably sell and license all types of software 
ranging from sophisticated analytical programs selling for thou- 
sands of dollars, down to simple accounting routines and games 
for personal computers 

The book will guide you step by step through the process of 
$30. No. 32 marketing, advertising, negotiating a contract, installing software, 

training users and providing maintenance and support It also contains sample software contracts 
that have been used in actual software transactions Also included are tips on how to negotiate 
with a large corporation, ways of avoiding personal liability, techniques tor obtaining free computer 
time and hints on how to run a free-lance software business while holding a full-time )0b 



55 



ESSEX PUBLISHING CO. Oept 6 

285 Bloomtield Avenue • Caldwell. N J 07006 

Order books by number Send check, money order (U S Si. VISA or Master Charge « Publisher pays 4th 
class shipping For UPS shipping (USA only) add $1 OOperbook For Air Mail shipping add $? 50 per book in 
the USA $6 00 in Mexico and Central America $1? 00 per book elsewhere NJ residents add 5% sales tax 
□ NolO QNo 16 ONo 32 □ Check enclosed OCreditcard CMlhclass OUPS DAir 



Name 



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City 



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Fnr taster shipment on credit card orders call 1201 1 783-6940 between 9 and 5 Eastern time. 



TRS-80, continued... 

Milwaukee area (no address in the letter), 
with a correction and two short 
programs: 

"In the May 1980 Strings you say 1 1 was 
quoting from page 2/3 of the Level II 
manual | that the TRS-80 tape file-name 
'may be any character other than double- 
quotes.' This is incorrect. 

"Since the file-name is a string, you 
may have a file-name such as A$. This 
means you can also have a command that 
has the form CSAVE CHR$(34) which 
will give you a file with double-quote (") 
as a name. 

'To prove it, make up a Basic program 
and save it as above. Then rewind the 
tape and type CLOAD "A". The TRS-80 
will attempt to find file A. When it finds a 
file with the name other than A it will 
print the name it found, in the upper right 
video area, and in this case a double- 
quote will be printed. 

"By selecting the number to be CHRSed 
from page C/2 of the Radio Shack Level 
II Basic Reference Manual, you can have 
tape files with the left arrow, underscore, 
etc., as a file-name, including graphic char- 
acters! 

(A brief note by Hank Obermeyer in 
the Oct. 1980 column, p. 183, said the use 
of CHR$ with string file-names gives a 
. total of 256 file-names.) 



"Here is another quickie: to find out 
the name of an unknown SYSTEM tape, 
type in and RUN this one-line program: 

1 INPUT#-1 ,AS:PRINT A$ 
Set the tape volume correctly and start 
the tape by pressing PLAY. After a while 
something like 

UTBUG 
will be printed. Ignore the U, and the rest 
is the SYSTEM tape's file-name. 

"Lastly, here is a program similar to 



count backwards by pressing the up-arrow 
key at any time. 

"Nasty print-control values are screened 
out and the program checks the port video- 
control line so that the screen will be 
CLEARed (and returned to 64 characters/ 
line if a CHR$(23) induces the 32 character/ 
line mode). It is numbered high so that 
you may merge it with a Basic program 
that you may wish to examine: 



10000 OEFINT A-Z 

10010 CLS: 'BASIC STARTS AT 17129 DECIMAL 

10020 PRINT "UP-ARROW = BACKUP: • 1-7 « DISPLAY DELAY RATE* 

10030 INPUT "START DISPLAY AT WHAT DECIMAL ADDRESS" ;N 

10IM0 PRINT Nf PEEK(N)f CHR« (PEEK (N) ) 

10055 IF INP<255>»63 CLS: PRINT N.23 

10050 IF PEEK<1«H00>=8 THEN I«=-l ELSE 1-11 'BACKUP ON UP-ARROW 

10060 IF PEEK<H352K>0 FOR D=l TO PEEKt H352>«50 : NEXT: 'DELAY 

10070 N=N+i: GOTO 10040: 'GET NEXT ADDRESS AND REPEAT 

10080 'THIS IS AN IMPROVED BASIC/R0M/ME>10RY ASCII PRINTER 

10090 'JAMES LISOWSKI 1980 



Figure 4. 



Short Program #9 (May 1980, p. 150). It 
gives the ASCII value of a ROM/RAM 
address (the user selects the starting 
address), but allows the print speed to be 
dynamically controlled by pressing the 
number keys 1 through 7, using the entry 
as a delay factor. 

"You can also run the display address- 



The up-arrow feature doesn't seem to 
work; can you change the program so it 
will? 

See also Short Program #14 (Dec. 19H0, 
p. 1%), which also displays the ROM con- 
tents "without messing up the screen with 
control characters." as the REM lines put 
it. rj 



P&T CP/M®2 Supports 

Hard Disk Storage 

for the TRS-80 Model II 

P&T CP/M 2 now supports two popular hard 
disk subsystems for the Mod II; thus you can 
combine all the features of the best CP/M for 
the Mod II with the speed and capacity of the 
hard disk drives. 

Cameo Electronics 

• uses mature cartridge disk technology for 
maximum reliability 

• supports up to 4 drives 

• removable cartridges make backup and 
data transfer fast and easy 

Corvus System 

• support for 10 and 20 Mbyte drives 

• special mirror utility allows backup by 
logical drive 

• supports up to 4 drives 

TlICHFr Prtc* $260 (FOB Gol eta) for P4T CP/M 2-hard 

K(^~VM disk version (CA residents add 6% sales tax) 

C32< PICKLES & TROUT 

1 KUU 1 P O BOX 1206. GOLETA. CA 93116. (805) 685-4641 

CP/M « a reentered trademark of 0«<tai Research TRS-80 ■* a trademark of Tandy Corp 



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.ifil^^lV 



Are you ready to tackle the biggest adventure of them all? 
Enter the world of Z-80 assembly language! Explore the 
innards of your TRS 80 with these Z 80 tools from MISOSYS 
Each program works on both Model I or Model III machines. 

THE BOOKs must be a part of your tools. Volume I gives you access 
to all math operations in your Level II ROM A symbol table of the 
entire machine noting over 500 addresses is included. Volume II tells 
you everything you wanted to know about the Level II I O printer, 
keyboard, video, and cassette routines are fully explained. Each 
volume has a fully commented listing of all the routines discussed. 
THE BOOKs will save you hours of assembler programming 
Each volume is priced at $14.96 or buy both for $24 95 Add $1 50 
S&H per book. 

What Z 80 tool kit is complete without a disassembler' DSMBLR I 
provides SYMBOLS for 16 bit and 8 bit relative references Cassette 
output loads directly into EDTASM Video display and 
printer output are provided 



paged 



TUTIL is a utility to rapidly examine, clear, initialize, move, and 
modify data in memory TUTIL can be used to compare two blocks 
of memory or search for up to 24 byte character strings You will be 
able to punch, load, and verify SYSTEM tapes. Modify registers by 
name. Includes MODIFY to alter your Mod I EDTASM for easier use. 

TUTIL & DSMBLR are $15 each or both for $25 Add $1.50 S&H. 



| MISOSYS DeptC2 

MasterCard 5904 Edgehill Drive 

Alexandria. Virginia 22303 
703 960 2998 MicroNET 70140,310 
CIRCLE 280 ON READER SERVICE CARD 




anaMeii 




for 
TRS-80 Models I & III 

SuperSoft LISP allows the TRS-80 to become 
a complete Artificial Intelligence laboratory! It 
is the tool that takes you to the frontier of Com- 
puter Science. 

The SuperSoft LISP is a complete and full im- 
plementation. (It is NOT a subset!) It contains 
an efficient garbage collector which optimizes 
the usage of user RAM, and supports the 
TRS-80 graphics. Below are some features: 



Runs in 16k level II (with only 6K overhead) 

Fully implements atom property list structure. 

PROG is supported. 

FUNARG device is implemented. 

Efficient garbage collection. 

Complete with LISP editor and trace. 

Allows complete range of single precision 

numeric data. 

Works with old as well as new ROMs. 

Contains 97 functions. 

Sample Programs. 



The LISP package is supplied on tape or 
discette and with a complete user manual. 



cassette version: 
(requires 16K level II) 

Disk version: 
(requires 16K disk) 

(manual only: $15.00) 



$75.00 
$100.00 




All Orders and General Information 

SUPERSOFT ASSOCIATES 

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CHAMPAIGN, IL 61820 

(217)359-2112 

Technical Hot Line: (217) 359-2691 

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CIRCLE 266 ON READER SERVICE CARD 



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Investment Analysis 

CS-3305 Cassette (32K) $24 95 

This program was originally 
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ments and investment decisions. 
Programs in this package include 
regression analysis, stock market 
simulations, market/stock values, 
risk analysis, time related invest- 
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Checking Account 

CS-3304 Cassette (16K I St 195 

CS-3504 Disk (32K) »24 95 

(Disk includes Text Processing, CS-3302) 

This program does not re- 
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of individual and monthly ex- 
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budget is 



Graphic Package 

CS-3301 Cassette (4K| St 1 95 



This package provides a 
variety ot interesting and useful 
graphing routines Graphing 
Package combines text and 
TRS-80 graphics to plot a variety 
of functions and other graphs. 

1. Bar Graph 

Bar Graph plots graphs for up 
to six different categories. An 
optional display does con- 
version to a line graph. 





Cartesian Coordinate 
Graphing 

This program plots a standard 
X. Y graph from a user entered 
function A special feature of 
this program automatically 
scales of the Y-axis. 

3. Polar Coordinate 
Graphing 

Rarely found in computer 
graphing packages, this polar 



graphing program provides 
plots of polar functions The 
program labels all axes, features 
automatic scaling, and lets you 
input the range and increment of 
the plot A unique and valuable 
program. 

4. Parametric Graphing 

Parametric functions are 
functions in which both x and y 
are expressed in terms of an 
independent variable t. The 
resulting graph is X vs Y. This 
program allows the user to input 
two parametric functions and 
produces a graph. 

5. Linear and Parabolic 
Regression 

These two programs are used 
for data analysis which can later 
be entered into the graphing 
routines. Regression routines 
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Tape Manager and Advanced Statistics 



CS-3303 Cassette 1 1 6K| $24 95 

This package may be the 
ultimate in statistical appli- 
cations for the 16K TRS-80. 
Attractively packaged in a vinyl 
binder with a large instruction 
booklet. Advanced Statistics 
will provide you with the ability 
to perform statistical tests never 
before available on small com- 
puters. Its cassette based data 
file system allows you to store, 
retrieve, and transform data 
files for use in several different 
tests. 

1. Tape Manager 

Tape Manager, the heart of 
the statistical file management, 
allows you to create, edit, and 
transform data files. Unique to 
this program are features that 
allow the user to perform 
transformations on variables, 
extract and create subfiles, and 
selectively copy records. Up to 
twenty variables and an un- 
limited number of cases can be 
processed. 

2. Descriptive Statistics 

Descriptive Statistics com- 
putes the mean, standard devi- 
ation, standard error of esti- 
mate, variance, skewness, kur- 
tosis, range, median, and quar- 
tiles for a variable and con- 
structs a histogram for each 
value A test scoring option for 
conversion of raw scores into 
percentiles is included. 

3. Two Variable 
Statistics 

This program calculates de- 
scriptive statistics for each 
variable. It performs a t-test for 
the difference of means, com- 
puting the product-moment 
correlation coefficient and its 
associated significance level. In 
addition, it performs linear 
regression and computes stand- 
ard error of estimate for Y. 

4. Crosstabulation 

This program constructs con- 
tingency tables for displaying 
frequencies, column percentages 
and table-wide percentages for 
each cell. It computes the Chi- 
square, the level of significance 
and gamma statistics. Tables as 
large as 10x10 may be evaluated 



CS-3505 Disk I32KI $24 95 

5. Regression-Trend 
Analysis 

This program computes least- 
squares regression coefficients 
from time-series or paired data for 
best-fit equations (linear, para- 
bolic, hyperbolic, logarithmic, 
power, exponential and cubic 
types). Calculates standard error 
of estimate for each equation and 
more 



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6. Multiple Linear 
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Performs multiple linear regres- 
sion using up to ten independent 
variables. The program computes 
both unstandardized and normal- 
ized coefficients, covariance, 
multiple correlation coefficient, 
and the standard error of estimate 





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7. Correlation Analysis 

Computes product-moment cor- 
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correlation coefficients with their 
associated significance levels. 

8. Analysis of Variance 

This program performs one-way 
and two-way analysis of variance 
for a maximum of ten groups in 
each control variable Statistics 
include the mean and standard 
deviation for each group, sum of the 
squares, degrees of freedom, mean 
square, F-ratios. and significance 
level. 



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198 



CREATIVE COMPUTING 



Economic and Ecology 
Simulations 



The Ecology Simulations 
series are a unique educational 
tool. They are based on 
"simulation models" developed 
by the Huntington Two 
Computer Project at the State 
University of New York at Stony 
Brook under the direction of Dr. 
Ludwig Braun. The programs 
and accompanying document- 
ation are written for self- 
teaching or classroom use and 
include background material, 
sample exercises and study 
guides. Graphic displays were 
specially developed by Jo Ann 
Comito at SUNY and Ann 




Corngan at Creative Com- 
puting The Ecology Simula- 
tions packages are a remarkable 
educational application of 
micro-computers. 



Ecology Simulations-2 

CS-3202 Cassette (16K I $24 95 
CS-3S02 Disk I32K) $24 95 



Ecology Simulations-1 

CS-3201 Cassette (16K| $24 95 
CS-3501 Disk(32K) $24 95 



1. Pop 

The POP series of models 
examines three different 
methods of population 
projection, including exponen- 
tial. S-shaped or logistical, and 
logistical with low density 
effects. At the same time the 
programs introduce the concept 
of successive refinement of a 
model, since each POP model 
adds more details than the 
previous one. 



2. Sterl 

STERL allows you to 
investigate the effectiveness of 
two different methods of pest 
control— the use of pesticides 
and the release of sterile males 
info the fly population. The 
concept of a more environ- 
mentally sound approach 
versus traditional chemical 



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methods is introduced In 
addition. STERL demonstrates 
the effectiveness of an 
integrated approach over either 
alternative by itself. 



3. Tag 

TAG simulates the tagging 
and recovery method that is 
used by scientists to estimate 
animal populations. You 
attempt to estimate the bass 
population in a warm-water, 
bass-bluegill farm pond 
Tagged fish are released in the 
pond and samples are recovered 
at timed intervals. By presenting 
a detailed simulation of real 
sampling by "tagging and 
recovery." TAG helps you to 
understand this process,. 

4. Buffalo 

BUFFALO simulates ti<e 
yearly cycle of buffalo 
population growth and decline, 
and allows you to investigate the 
effects of different herd 
management policies. Simula- 
tions such as BUFFALO allow 
you to explore "What if" 
questions and experiment with 
approaches that might be 
disastrous in real life. 



IQTest 



CS 3203 Cassette 1 16KI $14 95 



IO tests have been the subject 
of a great deal of controversy in 
the past few years. Yet. few of 
us know our IQ score. Now you 
can find out with our IQ test. 

Taking advantage of the TRS- 



80 s graphic capabilities, this 
test consists of 60 multiple 
choice questions. A special 
machine language routine does 
the scoring of the test and 
makes cheating almost impos- 
sible. 



1. Pollute 

POLLUTE focuses on one 
part of the water pollution 
problem; the accumulation of 
certain waste materials in 
waterways and their effect on 
dissolved oxygen levels in the 
water. You can use the 
computer to investigate the 
effects of different variables 
such as the body of water, 
temperature, and the rate of 
dumping waste material. 
Various types of primary and 
secondary waste treatment, as 
well as the impact of scientific 
and economic decisions can be 
examined. 

2. Rats 

In RATS, you play the role of a 
Health Department official 
devising an effective, practical 
plant to control rats. The plan 
may combine the use of 
sanitation and slow kill and 
quick kill poisons to eliminate a 
rat population. It is also possible 
to change the initial population 
size, growth rate, and whether 
the simulation will take place in 



an apartment building or an 
entire city 



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3. Malaria 

With MALARIA, you are a 
Health Official trying to control 
a malaria epidemic while taking 
into account financial con- 
siderations in setting up a 
program The budgeted use of 
field hospitals, drugs for the ill. 
three types of pesticides, and 
preventative medication, must 
be properly combined for an 
effective control program 

4. Diet 

DIET is designed to explore 
the effect of four basic 
substances, protein, lipids, 
calories and carbohydrates, on 
your diet. You enter a list of the 
types and amounts of food eaten 
in a typical day. as well as your 
age. weight, sex. health and a 
physical activity factor DIET is 
particularly valuable in 
indicating how a diet can be 
changed to raise or lower body 
weights and provide proper 
nutrition 



Social and Economic Simulations 



CS-3204 Cassette 1 16K) $24 95 
CS-3507 Disk I32K) $24 95 



1. Limits 



LIMITS is a micro-com- 
puter version of the well known 
"Limits to Growth" project 
done at MIT. It contains a 
model of the world that is built 
of five subsystems (popula- 
tion, pollution, food supply, 
industrial output, and resource 
usage) linked together by six 
variables: birth rate, death 
rate, pollution generation, re- 
source usage rate, industrial 
output growth rate, and food 
production rate. 

2. Market 

Market allows two or more 
people to play the roles of 
companies who are competing 



for the market for a particular 
product: in this case, bicycles. 
Each player makes market- 
ing decisions quarterly includ- 
ing the production level, the 
advertising budget, and the 
unit price of the product for 
his/her company. 

3. USPop 

USPOP allows the user to 
study many aspects of the 
United States' human demo- 
graphy (population change) 
including population growth, 
age and sex distribution. 
USPOP makes population pro- 
jections and investigates the 
consequences of many differ- 
ent demographic changes. 
(Available in November). 



AUGUST 1981 



199 




Over the last two months we've discussed 
the Atari display list (DL) and its graphics- 
characters capabilities in separate articles 
in Creative. In this column we'll look at 
some of the higher-powered features of 
the DL and provide a complete table of 
display list opcodes for future reference. 

First, a note from a friend at Atari. In 
the last article, we found the display list 
via: START = PEEK(741) + 256»PEEK 
(742) + 1. This can be simplified by using: 
START=PEEK(560) + 256*PEEK<561). 
The 560-561 pointers to the display list 
point directly to the DL, not to the byte 
before it, as do the 741-742 pointers, and 
are more reliable under strange operating 
conditions. I'm told. I'll use the 560-561 
pointers from now on. 

The display list, you'll recall, is a program 
written for a special processor called Antic. 
Antic handles much of the display gener- 
ation for the Atari and leaves the main 
6502 processor available for other work. 
Last month we discussed the character 
and graphics opcodes for the Atari: this 
month I'll present a complete list of all 
the opcodes, then devote the rest of the 
article to notes and explanation. I'll try to 
keep the list short and concise, for refer- 
ence purposes, and leave the explanations 
and examples for later. At first it will 
probably seem confusing, but read on. 

Display List Opcodes 

There are three main groups of DL 
opcodes. There are also some modifiers 
which may be applied to the "base" 
opcodes, much as a sharp or flat may be 
applied to a base musical note. However, 
just as certain notes may not be modified 
with a sharp/flat, certain DL opcodes may 
not be modified in certain ways. 

Blanking opcodes. When Antic encoun- 
ters one of these, he generates a certain 
number of blank display lines (background). 
He doesn't look to display memory or do 
anything else; he just takes a break and 
generates blan k scan lines. From one to 

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eight blank lines can be generated by 
these opcodes. The blank line, like any 
display block, extends all the way across 
the screen horizontally. 

Modifiers: Only a display list interrupt 
may be added to these opcodes. 

Character/Graphics opcodes. When 
Antic encounters one of these, he fetches 
bytes from display memory, determines 



the graphics mode, and puts something 
on screen. A complete list and discussion 
of these is available in "Atari Graphics 
Unveiled" in the June and July issues of 
Creative. 

Modifiers: Horizontal scroll, vertical 
scroll, load memory scan and a display 
list interrupt may be added here. 

Two special codes. JMP is a JUMP for 



Wank Lines 
















Number of blank scar 


lines 


He) 


opcode 


Decimal opcode 


1 






00 






00 




2 






10 






16 




3 






20 






32 




4 






30 






48 




5 






40 






64 




6 






50 






80 




7 






60 






% 




8 






70 






112 




Character / Graphics 


Modes 














Basic Graphics Mode 


Vertical 


Horizontal 


Colors 


Graphics/ 


Hex 


Decimal 


(if any) 


Size 


Size 






Character 









8 


8 




(2) 


C 


02 


2 


— 


10 


8 




(2) 


C 


03 


3 


— 


8 


8 




4 


C 


04 


4 


— 


16 


8 




4 


C 


05 


5 


1 


8 


16 




5 


C 


06 


6 


2 


16 


16 




5 


C 


07 


7 


3 


8 


8 




4 


G 


08 


8 


4 


4 


4 




2 


G 


09 


9 


5 


4 


4 




4 


G 


0A 


10 


6 


2 


2 




2 


G 


0B 


11 


— 


1 


2 




2 


G 


OC 


12 


7 


2 


2 




4 


G 


0D 


13 


— 


1 


2 




4 


G 


0E 


14 


8 


1 


1 




2 


G 


OF 


15 


Special Instructions 
















JMP 01 hex (01 D) 
















JVB 41 hex (65 D) 


















Table 1. 


Display List Opcodes. 









200 



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Atari, continued... 

Antic, it tells Antic to continue looking 
for instructions elsewhere. It is an equiva- 
lent to a GOTO in the display list. It is 
followed by a 16-bit address of where to 
continue. 

J VB is a jump to the start of the display 
list, and wait for a new screen refresh to 
begin (automatically). It is followed by a 
16-bit address, which by the way doesn't 
have to be the start of the original display 
list; it can also be a completely new list. 
The important point is that JVB waits 
until the screen is refreshing again before 
allowing Antic to continue. 

Modifiers: Only a display list interrupt 
may be added here. 

Modifiers 

To add a modifier to a given opcode, 
just add the number shown for that modifier 
to the base opcode, then use the number 
for the opcode. 

Horizontal Scrolling. This capability 
added to an instruction means that section 
of the display may be smoothly scrolled 
in a horizontal direction. Add 10 hex (or 
16 decimal). 

Vertical Scrolling. This capability allows 
smooth vertical scrolling. Add 20 hex or 
32 decimal). 

Load Memory Scan. (A three-byte 
instruction is implied if you use this 
opcode.) This tells Antic where to find 
display memory, and resets Antic's pointer 
to that location, no matter where he 
currently is. Add 40 hex (64 D) to use 
this. 

Display List Interrupt. The execution 
of this instruction causes Antic to force 



Before Memory 



Start 



Display 
Memory 




ftfter Memory 



Start 



i sp 1 ay 
Memory 




Diagram I. 



the 6502 processor to interrupt (to the 
location specified in locations 200 and 
201 H (512.513D). Requires writing to a 
location to allow interrupts. 

Notes and Discussion 

Concerning Modifiers: 

1 . Horizontal and vertical scrolling are 
neat additions to graphics capabilities. They 
are there to help make your job easier 
and provide some effects that you would 
otherwise have to work hard to generate. 
Scrolling is making the display appear 



Before Memory Rewrite 



Start 



D l sp 1 ay 
Memory 




After Memory Rewrite 



Start 



Pointer 

Display 
Memory 



Diagram 2. 




to "roll by —an object on the display comes 
into view, is run across the screen, and 
disappears on the other side. (The Atari 
coin-op game where you fly over enemy 
terrain, bombing targets that roll under- 
neath you, is an example of scrolling. 
This game could be implemented on the 
400/800, if you're looking for a saleable 
project, by the way.) Normally while editing 
you'll see the Atari scroll data up off the 
top of the screen. 

In order to have a display "scroll," we 
must first output it to the TV in unmoved 
format, then move it, then output it again. 
This will cause the display to shift once. 
Repeatedly doing this causes a scrolling 
effect. All our displays, generated by Antic, 
are stored in memory and are put on the 
TV 60 times a second, so what we have to 
do is change display memory in such a 
way that it will cause a scroll. 

If the display memory is changed so 
that all information in it is copied 40 bytes 
up. in graphics 0, then on the next refresh 
the former top line will be replaced by 
the information in the line below it (lines 
are 40 bytes long, remember). You've seen 
this effect when the Atari scrolls something 
up offscreen, as during a long set of 
PRINT'S. And, if we were to move the 
data in the display memory up just one 
byte, the screen would appear to move to 
the left, for the contents of the second 
byte would now be displayed in the TV 
position of the first byte, and so on down 
the screen. (See Diagram I.) 

This is a good way to do scrolling »/ you 
are working in assembly language. The 
amount of data that must be moved, 
however. (960 bytes in graphics 0) is so 
large that it becomes impossible for Basic 



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Atari, continued.. 




Scrolling Up Vertically 



Scroll Register • B 

All of LINE 3 is displayed 

None of LINE 6 is displayed 



Scroll Register ■ 3 

Part of LINE 3 is displayed 

Part of LINE 6 is displayed 



Scroll Register ■ 7 

None of LINE 3 is displayed 

fill of LINE 6 is displayed 



DiuKratn .1. 



to do the job quickly enough. There is a 
way to do scrolling from Basic without 
moving a large block of memory. Instead 
of having Antic look at the same place in 
memory for display memory and moving 
things around in memory, let's change 
where Antic looks and leave the memory 
alone. (Diagram 2.) 

For example, if we were to tell Antic 
that screen memory started one byte down 
from where it really did. Antic would 
miss the first byte of memory, and the 
entire screen would seem to scroll to the 
left. Antic wouldn't know the difference 
(or care), but to us, the screen will seem 
to have scrolled horizontally. If we were 
to tell Antic the screen memory starts 40 
bytes down from where screen memory 
actually starts, he'll miss the first line of 
data (assuming graphics 0), and the screen 
will scroll up. You can obtain some neat 
demonstration displays this way. Try 
Program 1 to scroll the screen horizontally. 
Program 2 to scroll it vertically, and 
Program 3 to do it both ways! These 
programs all just modify the pointer Antic- 
uses to find display memory, and are a 
good deal of fun to leave running in a 
computer store. 

However, all this gives us is coarse 
vertical/horizontal scrolling. When we 
rewrite display memory or such, we shift 
things eight dots or eight scan lines (in 



graphics 0). This gives us a very jerky 
display. So, Atari provided us with the 
capability to smooth out the scroll; you 
can shift the display vertically or hori- 
zontally the number of "fine" dots you 
need to make it smooth, then rewrite 
display memory or change Antic's pointer 
to continue. You cannot scroll more than 
the distance between coarse scrolls; you 
can think of it as fine tuning only between 
channels if you like. It is limited to 0-7 (or 
0-16 depending on mode) dots scrolled, 
which neatly fits our graphics scroll. 

On the Atari, scrolling is only a positive 
value. In other words, you cannot scroll 
something "down" using the scrolling 
register; you must start with it fully scrolled 
up and scroll it "less upwards" to achieve 
a downward effect. How much you wish a 
display scrolled up is written into a mapped 
memory location. 

Thus, in order to make a smoothly 
scrolling vertical display, we need to select 
our "coarse" vertical position with the 
display memory and such, then select how 
many "fine" scan lines to go up from that 
position. Presumably we would increment 
the number of lines to go up. to move the 
whole display up. When we reach seven 
increments, our capability to fine scroll is 
finished, and we have to rewrite display 
memory (and set our vertical scroll to 0) 
to get that eighth scan line up. Then we 



would start over with incrementing our 
vertical scroll location. A downwards scroll 
is nearly the same thing; just have it start 
at +7 scroll, then work down to 0, shift 
memory, and so on. 

The display list entry for a given display 
block must be modified to allow scrolling. 
If you write something to the scroll register, 
but don't change the display list, nothing 
will happen. 

Here are some details on how fine 
scrolling is implemented: 

Antic normally displays a fixed number 
of scan lines per display mode. Well, when 
we scroll vertically, Antic doesn't do this 
anymore. When Antic encounters the 
beginning of a "scrolled zone— "a group 
of display list opcodes with vertical scroll 
modifiers— he treats the beginning and 
end of the scrolled zone differently than 
he normally would. Display blocks in the 
middle of a scrolled zone are handled 
normally. When he first finds a scroll- 
marked display block, he doesn't display 
the normal number of scan lines for that 
display block. He only displays the bottom 
slices of the display block, the exact number 
determined by what is in the scroll register. 
Because the top line of the scrolled zone 
then becomes shorter than it normally is, 
the lines below it seem to move up. 
(Diagram 3.) 

The lines in the middle are displayed 
normally, then when Antic reaches the 
end of the scrolled zone, he only displays 
the top few lines of the last scrolled display 
block. Again, how many he displays is 
determined by the scroll register. This is 
necessary to make the total number of 
scan lines in the scrolled zone remain 
constant. Why? If the total changes, the 
display below the scrolled area will move, 
depending on the scrolled area. By having 
the top and bottom display blocks short, 
but the total of them adding up to one 
display block size always, we get a fixed 
size scroll zone. Also note that we will 
have "lost" one display block in the scrolled 
area: remember, only pieces of two display 
blocks, whose total is one display block, 
are shown. One stays missing. 

This is a strange but effective way of 
doing things. If you run Program 4, you 
will see vertical scrolling in action. This 
program writes two separate vertical 
scrolled zones into the display list, then 
scrolls them. Note that the display shrinks 
two scan lines when you run the program; 
this is the missing top of the top line and 
bottom of the bottom line (adding up to 
one display block height) in two places; 
hence there are two less displayed lines. 
Also note how the scrolling letters seem 
to disappear behind the fixed letters. They 
aren't really disappearing, they are just 
not being displayed completely. 

This capability requires some experi- 
mentation which may make clearer what 



204 



CREATIVE COMPUTING 



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J 



f A one-hour LP record of eight synthesizers may 
change your views about computer music forever 

Binary Beatles 



by David Ahl 

Computer music. Who needs it? It's mostly 
boring beep. beep, beeps or wildly modern 
stuff. It's certainly nothing you'd want to 
listen to more than once. That's what I thought 
about computer music and most of my friends 
agreed. 

In 1978 1 entered Yankee Doodle Dandy 
into my Software Technology system just 
to be different. Dick Moberg heard of it and 
asked me to perform in the Philadelphia 
Computer Music Festival. I agreed expecting 
to be the only one with something out of 
the ordinary. I was wrong. 

Computer Accompanist 

Nine individuals and groups performed 
in the festival There were the usual Bach 
pieces but even they were different. Gooitzen 
van der Wal performed the last movement 
of the 2nd Bach Suite in a unique way He 
played the flute solo while using the computer 
as accompaniment. 

Then Dorothy Siegel did the same thing. 
playing the clarinet solo pad of Wanhal's 
Sonata in b flat. The audience went wild. 

Hal Chamberlin played Bach s Tocatta 
and Fugue in d minor. But also with a differ- 
ence He used a large computer before 
hand to "compute" the waveform of every 



instrument playing every note. It took one 
hour of computation time for each two min- 
utes of playback time. The result could hardly 
be distinguished from the organ in the 
Hapsburg Cathedral. 

Don Schertz had a home brewed synthe- 
sizer truly mounted on a breadboard that 
allowed him to control 25 parameters of 
each note. It produced spectacular sounds 
in his arrangement of Red Wing. 

Singing Computer 

In 1962. D.H. Van Lenten at Bell Labora- 
tories produced the first talking computer. 
Bell engineers taught it to recite the soliloquy 
from Hamlet. Then they went one step further 
and taught it to sing Daisy both alone and 
accompanied by another computer. This 
was also performed at the festival. 

Yes. the Beatles were represented. Andrew 
Molda played Hey Jude on his COSMAC 
VIP system with a program called PIN-8 
(Play it Now). 

Superb Quality Recording 

All these pieces and twelve others were 
recorded with broadcast quality equipment. 
Because of audience noise, eight were re- 
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source and setting up the equil'zation curves 
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and record jackets. These were then shrink 
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We guaranteee that ever , LP record is free 
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The extensive descriptions of each of the 
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This 12 LP record of the Philadelphia 
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AUGUST 1981 



205 



CIRCLE 3S0 ON READER SERVICE CARD 



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■MM 



Atari, continued... 

I've been saying: Atari uses some tricky 
hardware to make their machines work 
as they do. Horizontal scrolling, by the 
way, should give you some entertainment 
as it involves modifying the amount of 
data per line in the display memory. 

The vertical scroll register is at D405 
hex (57239 D), and the horizontal scroll 
register is at 1)404 hex (57238 D). 

2. Load Memory Scan (LMS) 

This instruction is very useful and quite 
necessary to know about if you're doing 
much graphics work. It is a helpful tool 
for advanced graphics but using it is 
necessary in other applications due to the 
way the Atari hardware is designed. 

When Antic first learns where display 
memory is. it takes that 16-bit value and 
puts it into a register inside itself. When it 
wants data from memory, such as a line 
of characters. Antic looks to this register 
to find out where it currently is in display 
memory. It then fetches the byte at that 
location, and increments (he register so it 
points to the next byte. Trouble is the 
internal register is only 12 bits. (The other 
four bits are latches, if you're interested.) 
This means that as Antic goes along, if it 
hits a 4K boundary in memory (goes past 
a 1000 hex address point), it will run out 
of "fingers to count on" and start all over 
again! 

This has caused extreme frustration at 
Atari. I'm told, and is one of the most 
difficult-to-debug and commonplace prob- 
lems encountered in Atari programs. So 
remember, don't let your display memory 
cross a 4K boundary without resetting 
that pointer via a load memory scan. Place 
the 16-bit value of where to continue in 
display memory in the two following bytes. 
By the way. you've seen this instruction 
before; it's the 66 near the beginning of 
the display list. The 66 is a two (or graphics 
0, one line) instruction, with a 64 modifier 
added to it. (If you counted the display 
list example in the previous article, there's 
only 23 GR.O instructions, and one 66 
instruction to make up 24.) The 4K 
boundary means 4K in absolute memory 
address, not relative to the DL. 

This instruction also accounts for some 
of the graphics 8 display list instructions. 
Graphics 8 uses 7680 bytes of display 
memory, well past the 4096 byte Antic 
limit, and it thus needs this instruction to 
reset the pointer. If you dump the GR. 8 
display list, you'll see what I mean. 

I should also mention before it drives 
someone to insanity that the display list 
itself cannot cross a IK boundary because 
of the same sort of thing. Antic's pointer 
to where it is in display list is 16 bits long, 
but the top six bits are latches only; they 
cannot count. You must use the JMP 
instruction to pass a IK boundary in the 
display list (1048 decimal). If you start 
getting screwy display list results, you may 



have passed a IK boundary with the DL 
or a 4K boundary with the DM without 
using JMP/LMS to reset the pointers. 

3. Display list interrupts. 

Setting this bit (those of you with binary 
counting experience may now realize that 
the modifiers are just top bits set in the 
opcode) causes the 6502 processor to be 
interrupted, and sent to the location 
specified in 200 and 201 hex. This is a 
really handy capability; you can have the 
6502 busily doing something else, and when 
the display reaches a certain point, you 
can have the 6502 interrupt what it's doing 
for a special update. One example that 
comes to mind is changing a color register 
halfway down the screen to get more than 
four colors displayed at once. Using this 
capability requires some assembly language 
work, and I will provide an example of it 
in a later article. In the meantime, those 
of you who know assembly can POKE 
into 200 and 201. and use an RTI to get 
back once done processing. 

After the display list instruction is 
executed, you'll interrupt to your service 
routine. By the way, you'll also need to 
write a CO hex ( 192D) into location D40E 
(or 54286D) to enable this type of interrupt. 
Because of the usefulness of DLLs. I will 
include two general purpose assembly 
routines in a later article devoted to 
assembly aids for Basic (primarily in player- 
missile and DLI related items); one shifts 
all color registers to user-determined values 
wherever the user places an interrupt, 
the other is a kind of color display list, 
where every display block has five colors 
for the color registers and displays its 
data in those specified colors. 

Conclusion 

Well, there you have it, a complete list 
of DL opcodes. You can do a tremendous 
amount with this powerful tool. Look at 
what's been done on the Apple, a machine 
without the power of the display list, for 
example. Apple users have the equivalent 
of the Atari without the display list or 
other graphics tools and only a few graphics 
modes, and someone managed to imple- 
ment Galaxian on it! 

Coming up next month, now that we've 
covered the display list quite thoroughly, 
is Player-Missile graphics. This is the second 
graphics generation system on the Atari 
and will give you more power than ever. 
The display list alone is extremely powerful, 
especially with capabilities to synchronize 
the 6502 and interrupt on a given display 
block; Player-Missile should give you the 
final powerful tool to do about any ani- 
mations you wish on your custom display 
(list) background. 

Good luck and happy hunting with your 
Atari! (Our thanks to ComputerLand in 
Austin. Texas for allowing me to use their 
equipment to check these programs.) \3y 




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CIRCLE 220 ON REAOER SERVICE CARD 



AUGUST 1981 



207 




intelligent m 

computer 4 
games 



David Levy 



•**•« 






Correspondence is welcome 
Letters with interesting quest- 
a- /ons and ideas will be used in the 
5 column along with a response 
t No personal replies can be 
~T made. Send to David Levy, 104 
Hamilton Terrace, London NW8 
. 9UP. England 







GO-MOKl' 

This month we shall look at a game 
with an enormous number of possible 
moves at every juncture. The game is 
known as Go-Moku in most Western 
countries, though in Japan it is called 
Jenju. Go-Muko is a two-person game 
played on a Go board using Go stones; it 
is the size of the Go board ( 19 x 19) that 
gives rise to the enormous branching factor 
of the game tree. 

Black always starts and makes a move 
by placing a black stone on any of the 
intersections. Thereafter, the players move 
alternately and the player who first com- 
pletes a horizontal, vertical or diagonal 
line of five of his own stones is the 
winner. 

Since five men in a row is enough to 
win, if you get four men in a row with the 
two adjacent intersections (at each end 
of this row) vacant, then on the next move 
you can complete a row of five (unless 
your opponent can do so immediately). 
So an unblocked row of four men is a 
winning formation. It is now easy to 
understand that if you have a completely 
open row of three you are threatening to 
force a win by making it into an open row 
of four on the next move and then a row 
of five on the following turn. The threat 
to convert a completely open row of three 
into an open row of four can normally be 
blocked, simply by closing the row of 
three at one end and then, when the 
opponent places a stone at the other end 
of the row to make a row of four, it is 
possible to block the only open end of the 
row of four to prevent it becoming a row 
of five. 



Although it is possible to counter the 
threat of making one completely open 
row of three into a open row of four, it is 
obviously not possible to counter two such 
threats if they exist simultaneously. Thus, 
the most fundamental winning tactic in 
Go-Moku is to try to force a position in 
which you have, simultaneously, two 
completely open rows of three stones. 
The simple examples of Figure 1 will help 
to ilustrate these principles. 

The following rather obvious statements 
should be sufficient to teach the absolute 
beginner enough so that he can understand 
the principles of the game: 

A) The four black stones at N7. 07. P7 
and Q7 in Figure I form an open row of 
four. Unless, on his next move. White can 
complete a row of five stones elsewhere 
on the board and thereby win the game. 
White has no way to avoid defeat. If he 
plays on M7 then Black will play on R7 
and win. and vice versa. 

B) The white stones at C6, D6 and E6 
form a completely open row of three. 
Unless Black takes remedial action against 
this row, or unless Black can himself force 
a win on some other part of the board, 
this row of three threatens to win by 
becoming an open row of four. For 
example, if it is now Black's turn and he 
plays a stone on some useless point. White 
may place a stone at B6 for F6, in either 
case creating an open row of four which 
next move will become a winning row of 
five. 

C) If we now add to the board two 
more white stones, on F5 and G4. we can 
see that unless Black has a win on some 
other part of the board. White will win by 



making one or other of these rows of 
three into an open row of four on his next 
move. Black may stop the horizontal row 
by placing a stone at B6 or F6, or he may 
stop the diagonal row by placing a stone 
at H3 or D7, but he cannot do both 
simultaneously; and whichever row he does 
not stop immediately will grow on the 
next move into an open row of four and 
then into a winning row of five. 

Because this double threat, created by 
simultaneous rows of three, is absolutely 
decisive, the game loses much of its interest 
if no restriction is placed on the players. 
Try for yourself, playing Go-Moku against 
a friend and you will both soon discover 
that it is not terribly difficult to force a 
double threat situation early in the game. 
For this reason it is often the rule that a 
double threat may not be created if both 
rows of three are capable of being extended 
into open rows of four. In some cases this 
restriction is only applied to Black, in 
order to offset the advantage of the first 
move. 

Program Design 

Since Go-Moku is a zero sum, two- 
person game, we can employ most of the 
tricks of the trade that have been discussed 
in earlier articles in this series. The program 
will grow and search a game tree, using 
some sort of evaluation function to evaluate 
terminal nodes on the tree. The obvious 
problem is the size of the tree itself —with 
361 intersections on the board, even the 
alpha-beta algorithm will need to evaluate 
at least a quarter of a million terminal 
nodes when performing only a 4-pry search, 
and that assumes almost perfect ordering. 



vaiuaiu 
•rininal 
search. I 
dering. J 



208 



CREATIVE COMPUTING 



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Games, continued... 

The true number is likely to exceed five 
million terminal nodes in a 4-ply search, 
which puts the whole concept of full width 
search under a big cloud where Go-Moku 
is concerned. We will therefore need to 
find some way to prune the game tree, 
but more about that later. 

Evaluation 

As I mentioned in an earlier article, 
there is always a trade-off between selecting 
a sophisticated but slow evaluation func- 
tion, which provides a relatively accurate 
score for a game position, and the other 
extreme which is a fast but simple evalua- 
tion function which permits the search of 
a larger tree but which does not 'under- 
stand' so much when it is looking at a 
terminal node. William Blake once wrote: 
'A fool sees not the same tree that a wise 
man sees' and his words of wisdom were 
clearly intended for programmers working 
on computer games. 

In the case of Go-Moku. since the size 
of the game tree is so enormous, the use 
of a simple evaluation function with a 
deep tree search is clearly out of the 
question. In this sense, an important 
decision has been made for us by the very 
structure of the game itself. We must 
look at a relatively shallow tree, so we 
ought to ensure that our evaluation 
mechanism is wise rather than foolish. 

Let's start by considering what features 
might usefully be incorporated in our 
evaluation function— we shall expand their 
scope a little further on in this article. 

The key to a successful strategy is 
obtaining some of your own stones, in an 
unbroken row, in such a way that they 
could conceivably be extended into a row 
of five. Let us first define some variable. 
Wl = the number of single white stones 
which are in a row, column or diagonal in 
such a way as to allow the stone to be 
extended into a row, column or diagonal 
of five stones. 

Using the notation of Figure 1, imagine 
a white stone on Dl and black stones on 
Al, Fl and D5. There is no way that the 
stone on Dl can ever form part of a row 
or column of five stones, because the 
horizontal and vertical directions are 
sufficiently well blocked off by Black, but 
it is conceivable that the stone on Dl 
could form part of a diagonal of five stones, 
if White were to be able to place stones 
on E2, F3, G4 and H5. So in this case Wl 
would be 1, because this is the number of 
possible 5-rows that can be made using 
Dl. If there were no black stone on Al 
then the value of Wl would be 2 because 
D 1 could be part of a horizontal or diagonal 
5-row, and if there were no stone on D5 
either the value of Wl would be 3, since 
5-rows could be constructed horizontally, 
vertically and in one diagonal direction. 
Similarly, Bl = the number of single 



black stones which are in a row, column 
or diagonal in such a way as to allow the 
stone to be extended into a row, column 
or diagonal of five stones (which we call a 
5-row). 

And W2, B2, W3, B3, W4, B4. W5 and 
B5 are the corresponding variables for 
situations in which White or Black has a 
row. column or diagonal with 2, 3. 4 or 5 
of his own stones in an unbroken row. 

Let us assume for the sake of simplicity 
that all terminal nodes are at even depth, 
that is to say we only evaluate a position 
in which it is the program's turn to move. 
We shall further assume that the program 
is White. It is now necessary to assign 
weights to the features of the evaluation 
functions in such a way as to reflect the 
worth of a 1-row. a 2-row, a 3-row. a 4- 
row and a 5-row. Of course a 5-row has 
infinite value, in the sense that if you 
make a 5-row you have won the game, so 
the weighting assigned to W5 and B5 should 
reflect this fact, in the same way that a 
chess-playing program would have an 
infinite value assigned to the kings. 

Let the weightings which we assign to 
these variables be as follows: 
AW1 is the weighting assigned to Wl 
AB1 is the weighting assigned to Bl. 



a 5-row if you can. otherwise prevent 
your opponent from making a 5-row of 
his own if you can, otherwise make a 4- 
row of your own if you can, otherwise 
prevent your opponent from making a 4- 
row of his own if you can, otherwise. ..etc. 
The actual values of the AWi and the 
ABi should be chosen by intelligent guess- 
work to begin with, and then modified in 
the light of experience. I have discussed 
how this might be done, manually and 
automatically, in earlier articles in this 
series. 

Refinements to the Evaluation Function 

The function described above is simple 
to understand and to program, yet it 
encompasses the most important aspects 
of the game of Go-Moku. Nevertheless, it 
is rather unsophisticated and I should like 
to point out ways in which it might be 
improved. 

Consider an empty board on which we 
place one solitary white stone on the 
intersection El. This stone can conceivably 
form part of four different future 5-rows, 
or to be more accurate it can form part of 
5-rows in four different directions: hori- 
zontal, vertical, diagonal towards J5 and 
diagonal towards A5. So the value of Wl 



8 












7 
6 
5 
4 
3 
2 

1 
















1 


















( 


5 — ( 


)-< 


\ 
































































































































































/ 


V B C D E F G H I 


• M N O P R 



Figure I. 



Then the whole of the evaluation func- 
tion takes the form: 
(AWI x Wl) + (AW2 x W2) + 
(AW3 x W3) + (AW4 x W4) + 
(AW5 x W5) - (ABI xBD- 
(AB2 x B2) - (AB3 x B3) - 
(AB4 x B4) - (AB5 x B5) 
By ensuring that the weightings increase 
as the indices increase (i.e. AW5 AW4 
AW3, etc) we are using our evaluation 
function to represent the statement: 
5-rows are more valuable then 4-rows 
which are more valuable than 3-rows 
which are more valuable than 2-rows 
which are more valuable than 1-rows. 
And if we ensure that AB5 lies between 
A W4 and AW5. and that AW4 lies between 
AB4 and AB5. and that AB4 lies between 
AW3 and AW4... etc., we are using the 
function to represent the statement: Make 



producd by that stone is 4, one for each 
direction. Now let us remove this stone 
from El and place it on Jl. Is the stone of 
the same value on Jl as it was on El? 
Since the value of Wl for the stone on Jl 
is also 4, just as it was for the stone on El , 
it might seem at first as though the two 
stones are of equal value but they are 
not. Until the game nears its conclusion, 
much of the value of a particular 1-row. 
2-row or 3-row lies in its potential as a 
threat — the opponent must react in some 
way to counter the threat. Therefore, part 
of the strategy of the game lies in placing 
a stone in such a way as to compel the 
opponent to reply to one threat and then 
taking advantage of a different threat which 
the opponent was unable to meet because 
he had to attend to something more imme- 
diate. 



210 



CREATIVE COMPUTING 



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Games, continued... 

Let us consider the situation of two 
white stones on El and Dl. with the rest 
of the board being irrelevannt. If we add 
a third white stone to CI. a serious threat 
since a white stone on Bl or Fl would 
have to react to this threat by placing a 
black stone on Bl or Fl. White has then 
not accomplished anything in the horizontal 
direction because his play has now been 
blocked and if he puts a stone on Fl 
Black can counter on Al. But the placing 
of the third white stone on C 1 might well 
have much deeper implications— it might 
be part of a plan to create a strong 
formation over on the left hand side of 
the board, with a view to extending this 
formation into a winning threat later in 
the game. 

Now we come to the important differ- 
ence between having a single stone on El 
and having it on J 1. If the planned future 
activity is in the area of the A-column. B- 
column and C-column. it is less likely to 
be successful than if it is in the E-column. 
F-column and G-column. simply because 
in the former case this activity is bounded 
by the left hand edge of the board. If 
your area of activity is bounded in some 
way, either by an edge of the board or by 
a strong (or even impregnable) formation 
of your opponent's stones, you will be 
less likely to win than if your area of 
activity is not bounded. In the latter case 
you have more opportunity to use the 
area of activity to create further threats. 
What does all this mean in relation to 
our evaluation function? The obvious 
implication is that the weighting should 
vary in some way that reflects the number 
of vacant intersections to each side of a 
1-row. 2-row or 3-row. (The number of 
vacant intersections to each side of a 4- 
row is not important, since the 4-row itself 
will determine the outcome of the game 
at once.) In the above example it might 
appear as though the small number of 
intersections to the left of El might be 
compensated for by the larger number of 
vacant intersections to the right of El. 
and that therefore. El and Jl are of equal 
value. But if we think about the nature of 
the game it is clear that having a formation 
near the center of a row, column or 
diagonal, gives greater flexibility than 
having that same formation near one or 
more edges of the board. We should 
therefore adjust our weightings in some 
suitable manner, to reflect the desire to 
have useful formations nearer the center 
than the edges. One possible way of doing 
this is to subtract from a weighting AWi 
(or BWi). an amount Ci. where Ci is 
inversely proportional to ( 1 + number of 
vacant intersections between the end of a 
formation and its nearest edge of the board 
(or enemy stone) in the same direction). 
Thus, for a single black stone on the Dl 
intersection of an otherwise empty board. 



the weighting AB1 would actually be 
AB1— (1/3). for the component of the 
score that is related to the horizontal 1- 
row. This is because in a horizontal 
direction the nearest edge intersection to 
the 1-row on Dl is the intersection Al. 
which is two vacant intersections away 
from Dl. The weighting AB1 in the 
diagonal directions towards the left hand 
edge would be AB1 — 1/1; the weighting 
in the diagonal direction towards the right 
hand edge would be AB1 — 1/1 (these last 
three values are due to Dl being on the 
edge of the board). 

The suggestion to subtract a value that 
is inversely proportional to the 'freedom 
of movement' of a formation is given here 
as an indication of the shape that this part 
of the evaluation function should take. 
You might find it more satisfactory to 
subtract the square of that number, or 
some other function. 

Another important refinement of the 
evaluation function is needed to take care 
of those situations in which a stone of one 
color may have a nearby neighbor of its 
own color. For example, white stones on 
El and Gl with no other stones on the 
first horizontal row. The value of these 
two stones is clearly more than the value 
of two individual 1-rows. because the two 
stones can easily combine into a 3-row if 
White is permitted to play on Fl. On the 
other hand, two white stones with one 
vacant intersection between them are worth 
slightly less than a 2-row because with a 
2-row there are four distinct ways of 
creating a 5-row, whereas with two sepa- 
rated 1-rows there are only three distinct 
ways (since the vacant intersection between 
them must be occupied). This leads me to 
suggest that in a situation of this type we 
employ a weighting mid-way between that 
of a 2-row and the sum of two 1-rows. If 




©Creative Computing 



there are two vacant intersections between 
the two 1-rows. use a weighting one quarter 
of the way between that of two 1-rows 
and that of one 2-row. and if there are 
three vacant intersections take a weighting 
one eighth of the way between them. 
Similar logic can be used to suggest 
weightings for (say) a 1-row separated 
from a 2-row (in the same horizontal, 
vertical or diagonal) by one or two vacant 
intersections, though here as usual, your 
first guesstimate as to the size of the 
weighting will almost certainly need to be 
changed in the light of experience. 

The two refinements discussed here are 
probably necessary for a very strong 
program, but those of you who wish to 
keep things simple will, I'm sure, get an 
entertaining game from a program which 
employs only the most primitive form of 
the evaluation function. 

Combatting Enormous Tree Growth 

The potential size of the Go-Moku tree 
forces us to introduce some sort of forward 
pruning from the very first ply of search. 
The simplest way to do this is to employ 
the evaluation function also as a plausibility 
indicator. First your program generates a 
list of all the legal moves in the root 
position. (In fact it has this list readily 
available and updates it whenever a move 
is made in the tree — the updating consists 
simply of removing a now occupied inter- 
section from the list of legal moves.) The 
program then evaluates all the resulting 
positions at ply-1. using the evaluation 
function, and sorts the moves into descend- 
ing order of merit based upon these 
evaluations. The worst n percent of the 
moves on the list may then be discarded 
(n can be chosen to suit the execution 
speed of your program — I would suggest 
that you start with n = 90). You will now 
have a list of some 36 moves (at the start 
of the game) and from each of the 36 
positions you again generate and evaluate, 
discarding the worst (say) 92 percent of 
the moves at the next ply. The percentage 
of moves discarded goes up as the tree 
gets deeper and deeper, and this parameter 
can be adjusted, dynamically if necessary, 
so that the program is made to respond in 
any desired time frame. 

Your tree will now be no larger than 
the tree for a chess program, and move 
generation will be faster than for chess, 
so provided you code the evaluation routine 
in an efficient manner, you ought to be 
able to perform a search of 4-6 ply within 
a minute or two. if your program is written 
in assembler. 

Those of you who have been following 
my earlier articles will already have 
encountered the concept of the alpha- 
beta window and the killer heuristic, both 
of which should be employed in your Go- 
Moku program. In a large tree the killer 



212 



CREATIVE COMPUTING 



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214 



CREATIVE COMPUTING 



Games, continued... 

heuristic is particularly useful and the fact 
that you have sorted the moves prior to 
generation of the replies at each level will 
help considerably in the optimization of 
the alpha-beta routine itself. One other 
method of speeding the search is to avoid 
the need to re-evaluate those parts of the 
board that are not affected by a move in 
the game tree. You might, for example, 
keep several different components of the 
evaluation, and update only those affected 
by a move. For example, let us assume 
that the evaluation function has separate 
components for each horizontal, each 
vertical and each diagonal. If the program 
considers a move on the intersection A 1 , 
this move will in no way affect the evalua- 
tion of a formation in the J column, so 
part of the evaluation process need not 
be repeated— it is known to be unchanged. 
The more you speed up the evaluation 
process, the deeper the tree can grow, so 
any technique which updates the evaluation 
function in an incremental way is certain 
to be useful. 

Tactical Search 

In most board games it is possible to 
distinguish strategic play from tactical play. 
We have discussed this point before, with 
particular reference to chess and it is well 
known that the tree search should look 
deeper in those parts of the tree that are 
of greater tactical interest. In Go-Moku. 
tactical play is represented by threats, 
counter threats and moves that defend 
against threats. We have seen how the 
very existence of a 3-row constitutes a 
threat and it would be possible to argue 
that the creation of a 2-row is a veiled 
threat since the 2-row can easily grow 
into a 3-row. But I would recommend 
that we assume the evaluation function 
will be sufficiently smart to provide scores 
that represent fairly accurately the value 
of having a 2-row. It is the tactical value 
of a 3-row that is not so easy to measure 
and your program should therefore con- 



sider any move which creates a 3-row as 
being worthy of further consideration, even 
if it would otherwise be a terminal node. 
My suggestion for a tactical search is to 
examine any move which creates or blocks 
a 3-row or a 4-row or which creates a 5- 
row. This means that having grown the 
tree to what would normally be its full 
depth, the program examines the board 
to see if any 3-rows exist and if so, whether 
the opponent can block them. The program 
also examines moves which themselves 
create 3-rows. It does the same for 4-rows 
and it looks for moves which create winning 
5-rows. This process can, particularly during 
the later stages of the game, lead to a 
substantial increase in the size of the tree 
but tactics are extremely important in 
Go-Moku and it is essential for a strong 
program to have a good command of 
tactics. In order to be able to extend the 
tactical search to (say) 4 or 6 ply beyond 
the usual depth of search, it may be 
necessary to reduce the depth of the first 
part of the search. To ensure that your 
program responds within an acceptable 
amount of time, you should make your 
tree search iterative, with a mandatory 
cutoff after a certain maximum number 
of seconds. Your program might then 
perform a full 1-ply search, plus (say) 6- 
ply of tactical search; then if it has not 
consumed all of its thinking time it can 
sort the I -ply moves as suggested above, 
prune off 90 percent of them, generate 
the replies to the remaining ten percent 
and then perform a 6-ply tactical search 
from the resulting positions at depth 2- 
ply. Once again, if the search time is not 
exhausted, prune 92 percent of the second 
ply moves, generate the third ply moves 
and perform your 6-ply tactical search. In 
order to optimize the performance of your 
program, try playing around with the 
various parameters (not only the weightings 
in the evaluation functions, but also the 
percentage of moves pruned at each level 
and the depth of tactical search). □ 




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Creative Computing magazine is aimed at both 
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scores of applications for home computers. The 
down-to-earth style of the magazine encourages 
readers to have fun while learning. A dramatic 
computer graphic announces your gift. Only 
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Morristown. NJ 07%0. 



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AUGUST 1981 



215 



puzzles & ppcblems„.pi 





A Hole In One 

uzzsaw Bailey dropped into the Grits-N- 
Bits coffee shop the other day and told 
everyone about a puzzle he had just heard 
1 from a lumber salesman. The salesman 
showed Bailey a square piece of wood 
with a small hole drilled in it off center. 
"The problem," he told Bailey, "is to figure 
out the least number of pieces the board would have to 
be cut up into so that when you reassembled the pieces 
the hole would now be in the center of the board." 
Bailey left the piece of wood at the Grits-N-Bits and 
went home without telling anybody how it was dons. 
Can you tell the folks at the coffee shop how to solve 
this puzzle? (From the book Merlin s Puzzler 2 by Charles 
Barry Townsend and published by Hammond, Inc. 



O 







® 



The Brain Buster 

he gentleman pictured here, whose vocation 
obviously deals with numbers, is vainly trying 
to solve a mathematical puzzle in his head. 
The problem is a formidable one. You must 
add up all of the numbers from 1 to 100. Mr. 
Quiller has been working on this addition for 
over five minutes and he keeps losing track of 
which number he added last. What Mr. Quiller 
doesn't know is that there is a simple solution 
to this problem that would allow him to solve it 
in 20 seconds or less. Can you discover what 
this solution is? 

The Third Dimension Puzzle 

ur next problem should keep you busy with pencil and paper for quite awhile. Mr. 

Bruce Roland, of Meadville, PA, writes: "You are to draw the three-dimensional 

figure shown here with one continuous line. At no point can the line cross itself. 

However, you must keep in mind that this is a three-dimensional figure and some of 

the lines will go behind and under as well as over and in front of other lines." 

In other words, although you are drawing this figure on a two-dimensional surface, you must pretend 

that you are drawing it in space. When one line crosses another line it may really be going behind it. For 

ihis outer-space puzzle Merlin is sending Mr. Roland a copy of Merlin's Puzzler 2, a three-dimensional 

storehouse of puzzles and fun. 



Double Trouble 

ere are a couple of quickie (?) puzzles for you to work on. Below are pictured two simple 
equations. You must substitute the numbers 1 through 9 for the letters so that the equations are 
correct. 



A x B = CD 
CDxEF = GHI 




The Picnic Puzzle 

t the turn of the century Sam Loyd was America's favorite 
puzzle master. Try your hand at solving his famous "Picnic 
Puzzle." 

"When they started off on the great annual picnic every 
wagon in town was pressed into service. Half way to the grounds 
ten wagons broke down, so it was necessary for each of the 
remaining wagons to carry one more person. 

When they started for home it was discovered that fifteen 
more wagons were out of commission, so on the return trip 
there were three persons more in each wagon than when they 
started out in the morning. 

Now, who can tell how many people attended the great annual 
picnic?" 



216 



CREATIVE COMPUTING 



■I 



■ 






■■■■HHIM 



WM 





The Puzzle Club 



l the left is a panel from a cartoon/puzzle that we call 
The Puzzle Club. This cartoon strip will be a regular 
feature in MERLIN'S new activity magazine. Vote for 
MERLIN today!!! 



The Sesquicentennial Puzzle 

^■^^ erlin was showing me part of his stamp collection the 
m ■ other day when he ran across an interesting stamp 
II ■ commemorating 150 years of American puzzling. The 
Xl V particular stamp shown below depicts the famous "Broken 
*■ " House Number" puzzle. The puzzle, in brief, states that a 

house number sign, with a four digit number printed upon it, fell 
down and broke in half. It was noted by the owner of the house that if 
you added the two digit number on one piece to the two digit number 
on the other piece and then squared the result you would have a 
number equal to the original house number. (How he ever casually 
noticed this is beyond me.) That is; 30 + 25 = 55; 55 x 55 = 3025. 
The owner then set about determining how many other four digit 
numbers would yield the same results if they were "broken" in two. 
Why don't you try solving this problem on your computer? You might 
also see if there are any six digit numbers that would yield this type of 
result. 




The Three Prisoners 

rom one of Merlin's puzzling cousins across the sea comes this interesting presentation of an old problem. For his efforts 
Mr. Dan Simpson, of Sheffield, England, will receive a copy of Merlin 's Puzzler 2. Now for the problem: 
'Three programmers had been thrown into jail for writing unreliable software. They were all gloomily sitting in their 
cell waiting for dawn, when they were to be executed. As luck would have it that day was the birthday of the President of IBM and he 
decreed that he would grant the life of one programmer. The jailer, who was a frustrated computer user, decided on a fair way to choose 
who would be released. 

On the stroke of midnight the jailer entered the cell and spoke as follows to the three programmers. "You will see that I have three yellow 
hats, three green hats and three blindfolds. I shall blindfold you all and then place one hat on each of your heads. After I have removed the 
remaining hats out of sight I shall remove your blindfolds and if you can then see a yellow hat on the head of a prisoner you should raise 
your hand. Freedom will be granted to the first person to tell me the color of the hat on his own head." 

This he proceeded to do. Each prisoner looked warily at the other two and they all raised a hand, in fact they could all see two yellow 
hats. 

After a short time one prisoner (the one who read Creative Computing), smiled to himself, had a word with the jailer and walked to 
freedom. 

What color was his hat and how did he know?" Answers on page 224. 



YOUR LAST CHANCE TO CHANGE THE COURSE OF HISTORY 



Yes, fellow puzzlers, this is your last chance 
to help MERLIN launch a great new activity 
magazine. In case you missed the last two issues 
of Creative Computing, MERLIN wants to 
publish a magazine devoted to puzzles, games, 
riddles, quizzes, crossword puzzles, contests, 
stunts, mazes. The Victorian puzzles of Professor 
Hoffmann, a Dungeons and Dragons type 
puzzle/game, magic, puzzle cartoons like The 
Clue Club and The Puzzle Club, a cartoon 
version of the Change-The-Word puzzle that 
our readers like so well, and many, many other 
activities that could only be presented in a 
magazine produced by MERLIN. All of this 
can be yours if you act today! MERLIN needs 
to know that he has your backing in this project! 

After all, when he goes to see the Chancellor I Would you subscribe to such a magazine? 
of the Exchequer it's numbers that count, not 
guesses. 

So, give the old boy your support and fill out 
your ballot today! Remember, your vote really 
countsV. Five minutes of your time today will 
get you a great magazine tomorrow!!! 



Mail your ballot to: 
Charles Barry Townsend 
32 Hickory Drive 
Maplewood, New Jersey 07040 



Name. 
Street. 
City_ 
Age — 




.State- 



_Zip_ 



-Occupation. 



I 



I 



Would you like to see MERLIN publish a magazine devoted to puzzles, games, and other 
entertaining activities? Vote Y« 

Vote Yes ( ) 

What kind of subjects and articles would you like to have in a magazine of this kind? 
(puzzles, games, quizzes, crosswords, etc.) 

1 



AUGUST 1981 



217 



EVERYTHING YOU ALWAYS 
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VERSACALC! 



* SORT on any of up to 254 rows; 

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* AUTO— CATALOG from VISICALC. 

* AUTO SCREEN REFORMAT 

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III 



k 



Guide to Microcomputers, by Franz J. Frederick. Association 
For Educational Communications and Technology. 1126 16th 
St. NW. Washington. DC 20036. 158 pages, paperback $11.50. 
1980. 

Owning Your Home Computer, by Robert L. Perry. Everest 
House. New York. 224 pages, paperback $10.95. 1980. 
Without Me You're Nothing: The Essential Guide to Home 
Computers, by Frank Herbert with Max Barnard. Simon and 
Schuster, New York. 391 pages, hardcover $14.95. 1981. 

Although "assembled for the educational community" and 
prepared with funding from the National Institute of Education, 
the Guide to Microcomputers is of interest to anyone considering 
the machines the book focuses on: Apple II, TRS-80 (Model 
I). Exidy Sorcerer. Ohio Scientific C4P, Commodore/CBM/PET, 
Atari 800. and Texas Instruments 99/4. 

The first six chapters are useful to both educators and 
laymen: introduction, languages, disk operating systems, 
components of a system, peripherals, and service and 
maintenance. The writing is quite detailed and entirely objective, 
without bias toward or against any system. 

The last eight chapters are mainly for educators: computer- 
assisted instruction (CAD, timesharing and resource sharing, 
instructional and media-center applications, microcomputer 
projects in public schools, special applications, (electronic 
mail, networks, videodiscs), journals and magazines, software 
companies, and books, program guides and sources of 
educational programs. 

The last three chapters provide excellent, long and detailed 
lists of resources of interest to all. This is probably the best 
and perhaps the only) guide for educators, and despite being 
a little out of date (the Model I TRS-80 is no longer made), is 
crammed with more useful information than most other 
guides. 

Owning Your Home Computer is one of the most helpful, 
complete and well-written books available, not only as a 
guide for selecting a home computer, but for understanding 
companion areas such as networking, videotext. and help for 
the handicapped. 

Fifteen chapters cover The Home Information Explosion 
(mainly videotext), home computers. The First Generation 
(early machines). How to Buy a Home Computer, recent 
computers. The Handiest Home Computers (TRS-80, PET, 
Apple. OSI. Compucolor, Sorcerer, Atari, etc.), networks. 
The Mind Appliance. Ninety-Nine Common Things to Do 
with a Home Computer, educational uses, Home Computers 
in Your Work programming. Help for the Handicapped, 
home control, and the Thinking Computer of the Future. 

As for those 99 Common Things, they include: play games, 
hold game tournaments, create stories, compose and play 
music, learn computer languages, learn advanced math, manage 
family diets, analyze private portfolios, do word processing/text 
editing, and many more. 

Perry has obviously taken a great deal of time to make this 
a fine book with a wide coverage of home computers and 



218 



CREATIVE COMPUTING 






e views . . . 



adjacent areas. The book uses many pictures chosen for 
illustrative purposes and not just to pad out the book. The 
descriptions of the Handiest Home Computers include lengthy 
paragraphs on system description, memory, peripherals, disk 
drives, printers, software, and system prices. 

The appendix lists 1.050 home computer programs, by 
supplier and by category. A 4 I 2-page glossary is followed by 
a page listing 20 helpful books and six magazines. 

Although there are a couple of pages on computers that 
havent become popular, or which dropped quickly out of 
sight, such as the Bally Arcade, this happens with every such 
book, which begins to be out of date as soon as the writer 
finishes. 

Without Mt You're Nothing may be the first guide to home 
computers written by a famous author. Herbert has written 
over a dozen works of fiction, including the Dune series, 
which deal with the desert world Arrakis. 

According to the last sentence in the book. "Along with 
Max Barnard. Herbert has been devoting his time recently to 
developing his own home computer system which will operate 
his household appliances, manage his finances and help him 
produce his books." 

The first half of this book is so general that only two recent 
computers are mentioned by name: the M1TS Altair. which 
went out of production some time ago: and the DEC PDP-1 1 
family: "If money is no object, by all means consider the 
PDP-11. 

In the second half. Herbert, who believes the "the present 
philosophy of flowcharting stinks." comes up with his own 
approach, called Programap. which uses some 20 symbols 
that represent the different programming operations, such as 
a square containing a black rectangle and two knobs to 
represent a CRT screen, and a triangle hanging from a horizontal 
line to mean GOTO. These and the others are connected by 
the usual lines with arrows, and line numbers are added here 
and there, along with a column of brief descriptive phrases. 

Appendixes provide two programs in both Programap and 
heavily annotated Basic, for car maintenance and for mortage- 
interest payments. 

The writing is very good, but a guide to home computers 
that names only the Altair and PDP-1 1. isn't much of a guide. 
There's a list of microcomputer manufacturers, which includes 
Hughes Aircraft Co.. International Data Systems, and Sphere 
(iroup. 

For a real guide, get one of the other two reviewed here, 
which are among many that provide much more help, and 
cost less. 



Microprocessor Background For Management Personnel, by 

James Arlin Cooper. Prentice-Hall Inc.. Englewood Cliffs. 
NJ. 173 pages, hardcover $14.95. I9K1. 

The need for a book of this type became apparent to the 
author, according to the preface, while working on a 
microprocessor course for management personnel at Sandia 
Laboratories, where he is a division supervisor. This book 
was written for managers of technical people "who need to 
understand microprocessor basics without becoming expert 
users." 

Twelve chapters cover Background. Basic Principles. Data 
and Instruction Processing. Programming Techniques. Input/ 
Output. Bit-Slice Structure. Design Examples. Applications. 

AUGUST 1981 219 



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Personal Computer Service, ProSoft, and Ramware. 
BOOKS, leading publishers, 10% off 

MEDIA, Memorex and Dysan, deep discounts 
*CIE net, after 10%, $50-min., 3-or-more-item discount 



COMPUTER INFORMATION EXCHANGE 

Box 159 
. San Luis Rey CA 92068 



IAS and CP/M™ 

Out Integrated Accounting System (IAS) has always baen a good value, but 
wait until you see the latest version And. it's now available for the CP M 
operating system, too. Soma of the features include: 
Custom Chart of Accounts with a more flexible numbering system and 25 
character account names Improved financial reports, including an Income 
Statement with percent-of sales figures An expanded and more flexible check 
register. Expanded account names in AR and AP AR incorporates a modified 
open item, balance-forward account system with invoicing and statements 
AP has a more flexible check writing program as does the PR subsystem The 
GL. AP and PR check writing programs all are formatted for the same NEBS 
checks so you don't need three different types of checks The AR invoicing and 
statement programs are also formatted for NEBS forms All programs use our 
exclusive Skip Sequential file structure for improved speed and disk effi- 
ciency The user's manual has been expanded and includes sample printouts 
from most programs, and is written for the non-programmer 

The General ledger is * 150 00 and may be used as a stand-alone system The 
AR. AP and PR subsystems require the GL subsystem for proper operation GL 
plus one subsystem is S250 00. GL plus two subsystems is $325 00 and the 
complete package is S395 00 NOTE: the new IAS requires a 24 < 80 
cursor-addressable terminal. 48K of memory and one 8" or two 5'." disk 
drives CP/M" users must have the SoHo Group's Matchmaker, which we 
will provide free to the first 1 00 buyers of the complete IAS package |»1 1 00 
value). Matchmaker may otherwise be ordered with any IAS subsystem for 
$7500 

The IAS operator's manual may be purchased tor $25 00 (credited towards 
purchase). Please specify 8" SD (sod sectored) or 5' i" North Star disk and 
CRT type when ordering 

CP/M is I registered trademark of Digital Research 



master charge] 



ECOSOFT 

P.O. Box 68602 

Indianapolis. IN 46268 

(317) 283 8883 



views . . . bock reviews . 



The Selection Process (selecting hardware). Project Management 
Problems. Prognosis (the future). On Keeping Current (maga- 
zines, books, courses). 

Four appendixes cover computer mnemonics, glossary, 
microprocessor types ( 1802. 8080. etc.). and hex coding. 

The text gets quite technical in some places, showing, for 
example, a gate-level schematic of "data flow during addition": 
examples of a stack push-pop routine: complex flowcharts, in 
the design-examples chapter, of a war game, shooting gallery 
game, and an electronic combination lock: and schematics of 
the various basic microprocessor technologies (TTL, ECL, 
PMOS. etc.). 

The is the kind of book a manager can read from cover to 
cover if he needs or wants to know as much as possible, or 
skip over the heavier material without losing too much 
background essential for understanding later chapters, as can 
happen with nearly all computer textbooks. 

The writing is straightforward and direct, putting as much 
information as possible into each paragraph, page and 
chapter. 



Using CP/M. by Judi N. Fernandez and Ruth Ashley. John 
Wiley & Sons. Inc.. New York. 253 pages, paperback $8.95. 
1980. 

Another in the Wiley series of Self-Teaching Guides, this 
book, according to the back cover, will teach you to "create, 
erase, and copy files, run other programs, translate and test 
8080 Assembler language programs, print data from files, 
display the directory of a disk, and more." 

CP/M. or Control Program/Microprocessors, is a disk 
operating system for microcomputers based on the 8080. 
8085. and the Z-80 type microprocessor chip. It is a software 
package developed and distributed by Digital Research, and 
has become the most common microcomputer operating system, 
according to page vii. 

This book assumes you have a microcomputer and a CP/M 
package. The ten chapters are divided into frames. Information 
is presented, followed by questions that ask you to apply the 
information. The correct answers to these questions follow a 
dashed line after the frame, so you cover up the answers until 
you've written yours in the space provided. 

The ten chapters cover an introduction, Typing CP/M 
Commands. CP/M Built-in Commands. CP/M Transient 
Programs. The STAT Command. Using PIP, Introduction to 
ED. Editing Existing Files. Advanced ED Functions, and 
submitting Command Files. Three appendixes cover Changing 
Device Assignments. PIP Parameters, and Reference 
Summary. 

The book assumes that if you've gotten as far as buying a 
CP/M package, you understand enough about computers 
that it isn't necessary to teach the basics. Nevertheless, all 
computer jargon used is explained, such as 20K bytes, floppy 
disk, and video terminal. So if you're not all that familiar with 
computers, this book provides what is probably the easiest 
way to learn about CP/M. 



CIRCLE 154 ON READER SERVICE CARD 



So You Are Thinking About a Small Business Computer, by 

the staff of Computing in Your Business. Canning Publications 
Inc.. 925 Anza Ave.. Vista. CA 92083. 104 pages, paperback 
$12.50. 1980. 

This book is "especially suitable." according to the letter 
accompanying it. for "( 1 ) small business owners and managers 
with limited or no previous experience who are in the process 

220 CREATIVE COMPUTING 



ifc reviews . . . beck pe vie 



of selecting their first computer: and 1 2) computer professionals 
whose friends are asking them for help in selecting a small 
computer." 

Although the book has only % pages of text, it is large. 
8 1/2" by 11" in size and it's from the company that has been 
publishing since 1963 the well-known and authoritative EDP 
Analyzer, from which many pointed examples have been 
taken and placed amid the wealth of advice and common 
sense presented here. 

The ten chapters cover How a Computer Can Help You. 
How Computers Work. Hardware. Software. Vendors. The 
First Step— Familiarization. Selecting a Complete System. If 
Custom Programming is Needed. Using a Consultant, and 
What the Future Holds. 

The first appendix provides six pages of computer terms; 
the second. Some Leading Suppliers: major manufacturers 
(Burroughs. Honeywell. IBM. NCR. Sperry Univac). mini 
manufacturers (AM Jacquard. Basic Four. Data General. 
DEC. Hewlett-Packard. Microdata. TI. Wang), micro manu- 
facturers (Apple. Cromemco. North Star. Ohio Scientific. 
Radio Shack. Vector Graphics), turnkey system suppliers 
(Cado Systems. Qantell. remote computing services (ADP, 
Boeing, GE. etc.). 

This may well be the most practical of such guides, with 
much guidance in areas such as what can be expected (in 
customer support, marketing, peripherals, etc.) from manu- 
facturers in the three groups, where to find software packages, 
vendor characteristics, "what not to do" if customer program- 
ming is needed, precautions regarding consultants, etc. The 
photos are few but good: the book is thin but crammed with 
help. 



Basic-Pack Statistics Programs for Small Computers, by Dennie 
Van Tassel. Prentice-Hall Inc.. Englewood Cliffs. NJ. 239 
pages, paperback $16.95. 1981. 

This book of 33 statistical programs has two purposes, 
according to the preface: each program provides several 
statistical measurements, so the person using them "should be 
able to process much of their statistical data for small samples 
with the enclosed programs"; and second, "these programs 
can be used to develop an understanding of statistics." 

The third book in the Prentice-Hall Series On Personal 
Computing, it includes programs for descriptive statistics plus 
T-statistic. chi-square. independence, and two-sample tests, 
plus examples and exercises designed to "teach the user how 
to use the programs. . . . While using the programs, the user 
can enter in several sets of varying data and see how the 
output statistical measurements vary as the input data 
varies." 

Each program is presented in three parts: description, 
sample run. and a listing. The Basic used is described as being 
at a level that will make the programs transferable to most 
computers. Each program description contains a "bugs" 
paragraph that describes any deficiencies or limitations in the 
programs. 

Van Tassel, who has written frequently for Creative, writes 
very clearly and as simply as possible. His book provides a 
painless way to learn about statistics. If you like it. you may 
be interested in his second book of statistical programs, in 
preparation at this writing. Hopefully the printouts will use ;i 
newer printer and/or ribbon than some of the early ones in 
this book, which are a little hard on the eyes. A minor 
problem, however, in an otherwise excellent btx>k on a complex 
subject made simple and readable. □ 

AUGUST 1981 221 



ADD EXCITING MUSIC 
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MEASURE 3 SUB 9 9474 

END 

sAusa 
A L F's 9 -voice Music Card MCI 
is only $195. 

Here's what our customers have said: 

(Excerpts from unsolicited letters. Copies of original letters available on request.) 

About the A L F system: 

It's a rare enough occurrence when hardware/software lives up to one's 
expectations For something to exceed one's wildest hopes — as the ALF 
synthesizer certainly does — is a real treat My congratulations to all 
concerned 

— Dhahran. Saudi Arabia 

I myself have told several people that next to a disk. I consider the |ALF| 
synthesizer to be the most important peripheral they could purchase tor their 
system Very excellent |Ob! Keep up the good work. 

— Oak Ridge. Tennessee 
I recently purchased 2 of your Apple music boards Out of the peripherals I 
have for my Apple. I enjoy them the most It has to be the most enjoyable 
thing that has ever been invented I hope you continue to develop products as 
clever and enjoyable as this one The Entry program has to be one of the most 
sophisticated programs I have ever seen It proves that a hardware manufac- 
turer DOES have the ability to also produce quality software It is almost 
worth the price of the boards just for the Entry program. 

— Burbank. California 

About ease of use: 

I have had my Music Card MC1 for a little more than a week now and I have 
almost completed entering "The Maple Leaf Rag'' I found it to be a lot 
simpler than I thought and so I am very, very pleased My family isn't because 
I sit up to all ends of the night playing with the blasted thingi 

— Cypress. Texas 
ALF has opened up my head and ears and enabled me to do things musically 
which I would like to be able to do on (conventional] instruments As much as 
I love the instruments I try to play. I just don't have the talent and technique to 
play what is in my head By golly, the ALF board doesn't know about my 
limitations, though I can play hell out of that thing, playing notes and tempos 
which previously have existed only in my head Many thanks from a frustrated 
musician and satisfied ALF "player ". 

— Demopolis. Alabama 

About documentation: 

I don't know much about hardware, but I have been a programmer for 15 
years and I have never seen a better piece of software documentation than 
your user manual It is a joy lo study I 
— Lancaster. California 

About the competition: 

Recently, I purchased an [ALF] 9 voice board and a couple of music al- 
bums all I can say is that I wish I had listened and played with it before I 
purchased the Mtn Hardware board It sounds about the same and is vastly 
superior in software, ease of use. and price The Entry program is a |oy to use 
and it's easier than Mtn Hardware's, but then. I guess you guys know that 
already (Oh yes. you wouldn't happen to know of anyone that wants to buy a 
Mtn Hardware system' $450 or best offer') 
— Kirkland. Washington 

I would like to tell you that after having used the system ONLY ONE DAY. that 
I am absolutely delighted with it In addition. I purchased the three boards 
although I ALREADY own Mountain Hardware's music system Now that I 
have seen and own your system. I am putting my "old'' one up tor sale I think 
that your software makes it far easier to enter music, and that the software 
routines allow for far greater flexibility Again. I extend my compliments to 
you As I said. I have owned another music system, and consider myself 
therefore, qualified to make a judgement between the use of the two Yours is 
the clear choice! 

— Levittown. New York 

See your local Apple 8 dealer 
or write: 




Appl. 



ALF Products Inc. 

1448 Estes Denver, CO 80215 

n a ttdcWmdrk of Appl*- Computer Inc 






m&4m 




Cunard Hotel London 10-12 September 1981 




The Show which brings your market direct to you . . . 

The Personal Computer World Show is the UK exhibition exclusively for the small 
computer industry. It is your opportunity to meet, face-to- face, potential buyers who 
visit the Show specifically to see demonstrations and discuss the application of 
your products. 

This is the Show where buyers come to buy ... not just look. 

To discuss how the 4lh Personal Computer World Show could form the focus of your NNI promotional calendar contact 
Timothy Collins on O I -4Mo 19S1 or write to him at Montbuild Ltd. II Manchester Square. London. Wl. ENGLAND 





Computer Bum- black design by car- 
toonist Monte Wolverton on gray 
denim-look shirt with black neckband 
and cuffs. 



Creative's own outrageous Bionlc Toad 
in dark blue on a light blue shirt for 
kids and adults. 



Give your 
tie a rest! 



All T-shirts are available in adult sizes 
S.M.L.XL. Bionic Toad. Program Bug and 
Spacewar also available in children s sizes 
S(6-8).M(10-12)andL( 14-16) Made in USA. 
$6 00 each plus 75 C shipping. 

Specify design and size and send payment 
to Creative Computing. 39 E Hanover Ave . 
Morris Plains. NJ 07950. Orders for two or 
more shirts may be charged to Visa. Master- 
Card or American Express Save time and 
call toll-free 800-631 -811 2 ( in N J 201-540- 
0445). 



Plotter display of PI to 625 Places in 
dark brown on a tan shirt. 




Crash Cursor and Sync from the comic strip 
in SYNC magazine emblazoned in white on 
this black shirt 




The Program Bug that terrorized Cyber- 
nia in Katie and the Computer is back 
on this beige t-shirt with purple design. 
You can share the little monster with 
your favorite kid. 



Roll down the block with this little 
black Robot Rabbit (on a bright orange 
t-shirt) on your back and you can 
intimidate every carrot, radish or cuke 
in your way. 



CIRCLE 350 ON READER SERVICE CARD 









•fade 

Service Advertiser Page 


xtcadvei 

Reader 

Service Advertiser 


f-tfe 

Page 


sens. 

Reader 

Service Advertiser Page 






102 Aardvark Technical Service 116 


1 74 Exatron 


15 


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174 


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103 Addmaster 130 


1 78 Frederick Computer Products 


179 


175 Program Store 133 






146 Advanced Computer Products 169 


179 GRC Assoc. 


168 


180 Protecto Enterprises 135 






* ALF Products 221 


199 Gulf Breeze Computer Store 


203 


195 Quality Software 27 






106 Apple Computer 184-185 


205 Hayden Book Co 


138 


188 Racet Computes 181 






109 ASAP Computer Products 171 


206 Hayden Book Co 


127 


184 Radio Shack 73 






116 ASCII 173 


153 Hayes Microcomputer 


16 


244 RCA 42 






114 Atari 83 


160 Hayes Microcomputer 


111 


Realty Software 139 






107 Aurora Systems 218 


220 Heath Co 


40-41 


Retail Roster 209 






110 Automated Simulations 7 


221 Heath Co 


97 


229 Sebree s Computing 207 






115 Beagle Bros. 168 


190 Howard Industries 


21 


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270 Blue Lakes Computing 219 


144 Huntington Computing 


85 


194 Skyles Electric Works 123 
261 Softsel 106 






129 Broderbund Software 170 


147 IDSI 


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104 Bucks Software Swap 136 


151 Information Unlimited Software 


23 


262 Soft-tools 125 






119 C & S Electronics 173 


208 Infoworld 


177 


196 Software Emporium 98 






118 Central Point Software 147 


152 InsoftCorp 


121 


269 Software Publishing Corp. Cover 3 






117 CE Software 49 


207 Integral Data Systems 


39 


198 Software Source 152 






111 CLOAD Magazine 191 


105 Iridis 


153 


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113 CLOAD Magazine 191 


219 Krell Software 


31 


271 Spectral Assoc 161 






231 Color Software 147 


210 Lazer Microsystems 


126 


189 Spectrum Software 51 






126 Comm Data Systems 151 


216 Lifeboat Associates 


157 


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278 LNW Research 


193 


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" Comp-U-Con 80 


162 Magnolia Microsystems 


207 


204 Stonehedoe Computer Co. 181 






112 CompuServe 68-69 


1 65 Mark Gordon Computers 


177 


201 Strategic Simulations 37 






108 Computers-by-Mail 172 


223 Mastertype 


123 


268 Street Electronics 53 






217 Computer Consultants of Iowa 100 


228 Meta Technologies Unlimited 


167 


187 Sublogic 211 






141 Computer Exchange 119 


167 Micro Ap 


95 


266 Super Soft 197 






143 Computer Exchange 59 


197 Micro Architect Inc. 


152 


Sybex 100 






124 Computer Information Exchange • 14 


155 Micro Lab 


43 


257 Tab Sales 139 
218 Tampico Labs 165 
202 Tarbell Electronics 140 






122 Computer Information Exchange 220 


156 Micro Lab 


45 






148 Computer Mail Order 203 


185 Microlearningware 


152 






128 Computer Shopper 218 


* Micro Magazine 


205 


222 3 G Software 165 
276 Thunderware Inc. 79 
236 TNWCorp 151 
193 Total Information Service 118 






145 Computer Specialties 173 


163 Micro Management 


87 






149 Computer Station 141 


168 Microsoft Consumer Products 


103 






* Computer Store of the Month 163 


247 Microsystems 


143 






123 Computer Trader 215 


224 Micro Technology Unlimited 


145 


181 Transnet 117 






132 Computerville 171 


212 Micro Works 


190 


237 Triangle System 140 
183 TSE Softside Cover 2 






130 Computers Wholesale 143 


157 Mini Micro Mart 


5 






138 Computromcs 89 


166 Minnesota Software 


142 


240 Videx 35 
146 Vista Computer Co 169 






137 Computromcs 91 


280 Misosys 


196 






135 Computromcs 93 
133 Concord Computer Components 197 


191 Mountain Computer 
232 Mountain Software 


1 
174 


* Windjammer Barefoot Cruises 213 






140 Consumer Computer Mail Order 128 


225 Muse Software 


175 








161 Cottage Software 137 
171 CPU Shop 63 


226 Muse Software 


178 


Creative Computing 






227 Muse Software 


180 








139 Creative Discount Software 153 


* National Computer Show 


182 


300 Apple Software 57 






120 Cygnus Microsystems 174 


253 NEC America 


8-9 


300 Apple Software 154 






125 DakmSCorp 10 


Northern Technology Books 


29 


300 Apple Software 155 






127 DakmSCorp 113 


1 72 Ohio Scientific Cover 4 


300 Atari Software 201 






182 Data Soft 13 


213 Omega Sales 


75 


350 Best of Creative Computing 214 






150 Designer Software 33 


242 Omikron 


2 


350 Blister Ball 19 






121 Digibyte Systems Corp 65 


243 Omni Resources 


105 


350 Catalog 123 






214 Discount Data Forms 215 


248 On-line Systems 


47 


350 Creative Computing Index 100 






158 Discount Data Products 77 


250 Orange Micro 


149 


350 Computer Rage 206 






131 Discount Software Group 67 


251 Osborne/McGraw Hill 


114 


350 Computers for Kids 194 






134 DJAI Systems 25 


169 Pacific Exchanges 


109 


350 Problems for Computer Solution 43 






136 Dynacomp 54-55 


169 Pacific Exchanges 


138 


350 Sourcebook of Ideas 162 






209 East Coast Computer 207 


169 Pacific Exchanges 

186 Pan American Electronics 


123 


' Subscriptions 164 






154 Ecosoft 220 


151 


300 TRS-80 Software 71 






164 Edu-ware Services 161 


239 Peripherals Plus 


131 


300 TRS-80 Software 198-199 






173 Ehinger Assoc 137 


239 Peripherals Plus 


159 


350 T-Shirts 223 






142 Electronic Specialists 203 


239 Peripherals Plus 


115 








Essex Publishing 195 


239 Peripherals Plus 


176 


•Write Advertiser Directly 






nil7 7lo «X>ftc»*f*.t#n*nr» 


The Third Dimension Puzzle: First, 


number 


The Puzzle Club: Slice the pie in half. Slice it 




k»VM.Ki C9IIOWG»|«£) 


the corners and where the X lines cross as 


in half again the other way. Stack the four 




shown in the diagram. Then draw one continuous 


pieces on top of each other. Cut the stack in 


A Hole In One: The least number of pieces (he 
puzzle can be done in is two. Cut out the piece 
outlined by the doted line, turn it end for end 
and replace it in the board. The hole will now 


line between these points as follows: ( 
1 to 5 to 6 to 2 to 10 to 1 to 3 to 7 to 9 
to 8 to 7 to 5 to 10 to 6 to 8 to 9 to 4 t< 
Do this in this order without lifting the 
i ? 


}o from 
o3to4 

.2ml. 
pencil. 


half. You now have 8 pieces from just three 
cuts of Antoine's knife. 

The Sesquicentennial Puzzle: There are only 
three four digit numbers that yield this result: 
9801, 2025, and 3025. 


be in the center of the board. 




j 


^~12^ 


\ 




\ 




V 




—-i 








k 




The Three Prisoners: The hat was of course 




^ 


^ 


^k 


yellow. Call the three prisoners A, B and C and 
let A be the one who gained his freedom. 






7 D 










Double Trouble: 3 x 6 = 18. 18 x 54 = 


972. 


Prisoner A argues as follows: Consider the 
case where one hat is green (it must be mine) 




The Picnic Puzzle: There must have been *uu 


then another prisoner (say B) would argue, I 


The Brain Buster: Try pairing the lowest and 


picnickers who would be seated 9 to a wagon 


(B) can see yellow on C, C can't see his yellow 


highest numbers: 1 + 100 = 101; 2 + 99 = 


if there were 100 vehicles, or 10 to a 


wagon 


and A has green, so 1 (B) must be the yellow C 


101 : 3 + 98 = 101 ; etc. In the set of numbers 1 


after 10 of the wagons had broken down. When 


can see so 1 (B) must be yellow. But no one 


through 100 there are 50 such pairs. Thus, SO x 


they started for home with 75 wagons 


, it was 


argued this way so we can't have the case 


101 = 5050 would be your mental solution. 


necessary for 12 persons to ride in each 


wagon. 


where one is green. So I (A) must be yellow. 






224 




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The jjfs: software series 



j 




0* 



Stearic 



ARrsonal Information 
Management System. 



Your APPLE* ccxnputer really can track purchase 
orders and inventory, analyze your investment records, 
maintain client and patient histories, or even catalog 
magazine ahstracts and your stereo collection. 
Software Publishing Corporation has the answer 
and it doesn't require programming! 

We call it the PFS software series- an easy 
to use yet powerful set of programs that let ycxi 
design a system that's versatile enough to 
manage almost any kind of information. 

PFS, the personal filing system, lets 
you design your own form on the screen 
for organizing information. Once it's cre- 
ated you just fill in the Hanks. Looking 
up what ycxj've filed is just as easy. PFS 
can search for a number, a single piece of 
data, a word within a page of text, or 
any combination. All forms that match 
are displayed on the screen for browsing, updating, ex- 
panding, or printing. PFS can even create mailing labels. 

PFS: REPORT, the personal report system, uses 
the files PFS creates to produce a report tailored to your 

PFS i> .i trademark ot Software Publishing Corporation. 




requires a 48K, 16- 
APPLEII 



specifications. Just mark the information you want listed 
and PFS: REPORT will sort it and let you specify head- 
ings, totals, averages, counts, and calculations. You can 
save your report design for use on a regular basis. 

PFS and PFS: REPORT come with simple 

self teaching manuals plus a support plan that 

includes program updates and factory experts 

ready to answer your questions. And all of this at 

an affordable price. Each program is priced 

below $100. 

The PFS software series is differ- 
ent. It is not a specialized application 
package nor a complex programmer 
oriented data base manager. It's a per- 
sonal information management sys- 
tem that lets you store, retrieve, and 
report information your way without 
programming. The PFS software series 



sector disk based 
system 

is available through your local dealers. If they don't carry 
it have them give us a call at (415) 368-7598 or 
write to us at Software Publishing Corpora- 
tion, PO Box 50575, Palo Alto, CA 94303. 

APPLE" is a registered trademark of Apple Computer, Inc. 



m 



Software Riblishing Corporation 

CIRCLE 269 ON READER SERVICE CARD 



Educator, Entertainer, Accountant, 



Your Challenger 
Personal Computer. 

Through the miracle of modern 
technology, a complete computer as 
powerful as the multimillion dollar 
room-sized computers of a few years 
ago can be put in a package the size of 
a typewriter and sells for as little as a 
color television set! 

Through its years of microcomputer 
experience, Ohio Scientific has effec- 
tively channeled this tremendous 
computer power into a "friendly" 
computer with hundreds of personal 
uses, via a huge software library 
of programs for a broad range of 
personal, home, educational and 
business use. 

This available software allows you to 
use and enjoy your computer without 
becoming an expert. The Challenger, 
however, is a powerful, general 
purpose computer which can be pro- 
grammed in several languages by 
those who choose to. 

Here are just a few of the popular uses 

of an Ohio Scientific 

Challenger 

Computer: 

Education 

The personal 
computer is 
the ultimate 



educational aid because it can enter- 
tain while it educates. Software 
available ranges from enhancing your 
children's basic math, reading and 
spelling ability, through tutoring high 
school and college subjects, to 
teaching the fundamentals of com- 
puters and computer programming. 

Entertainment 

Many of the Challenger's games 
educate while they entertain, from 
cartoons for preschoolers to games 
which sharpen mathematical and 
logical abilities. But, entertainment 
doesn't stop here. The Challenger's 
graphics capabilities and fast opera- 
tion allow it to display action games 
with much more detail than the best 
video games, providing spectacular 
action in games such as Invaders, 
Space Wars, Tiger Tank and more! All 
popular sports such as golf, baseball 
and bowling are available as simulated 
computer games as well as many 
conventional games such as chess 
where the computer plays the role of a 
formidable opponent. 



Accounting 

Your Challenger computer can keep 
track of your checkbook, savings 
account, loans, expenses, monitor your 
calorie intake and your biorythms. 

If you are involved in a business, you 
can use it to do word processing; ac- 
counting, inventory control, order pro- 
cessing, customer lists, client records, 
mailing labels and planning. 

And more: 

This may seem like a lot of uses, but it's 
only the tip of the iceberg for a general 
purpose computer. For example, your 
Challenger can be expanded to control 
lights and appliances, manage your 
energy usage and monitor for fire and 
break-ins. Furthermore, it can commu- 
nicate with you, with other computers 
and the new personal computer infor- 
mation services over the telephone. 

In fact, the uses of general purpose, 
personalized computers are expand- 
ing daily as more and more people 
discover the tremendous capabilities 
of these new 
technological 
wonders. 

Ohio Scientific 
offers you four 
personalized 
computer sys- 
tems starting 
at just $479. 




a Apfr^ CM Company 
1333 SOUTH CHILLICOTHE ROAD 
AURORA, OH 44202 • (21 6] 831-5600